Staged post-training of multimodal foundation models chains vision-language alignment, reasoning distillation, and domain tuning, yet how each phase trades capabilities against the others remains under-characterised. Tracking an 8.4B-parameter model from an un-fine-tuned baseline through three training phases on Japanese financial documents (evaluated on five text-input benchmarks), we find the phases interact non-additively: math-only distillation overwrites the financial knowledge acquired earlier even as procedural math skill survives, and the domain phase repairs more than it installs. A skip-phase ablation is best for domain knowledge but forfeits numerical-reasoning gains, so per-phase contributions are not decomposable and the best checkpoint is task-dependent, with implications for checkpoint retention and scheduling rather than added stages.
Figures & tables
Phase
Updated
Primary Objective
P1-S1
Projector
Alignment of image and language embeddings (vision and LLM frozen)
P1-S2
Vision + Projector + LLM (LoRA)
Visual instruction following in Japanese
P2-S1
LLM (QLoRA)
Chain-of-thought distillation for math reasoning
P3-S1
LLM (LoRA)
Text-only financial-domain adaptation
P3-S2
Projector + LLM (LoRA)
Visual domain QA on government financial documents
Table 1: Training phases and modules updated at each stage (P = Phase; S = Stage). “Vision” = SigLIP-v2 encoder; “Projector” = 2-layer MLP; “LLM” = llm-jp-4-8B-Instruct. “LoRA” ( Hu et al., 2022 ) denotes LLM adaptation via low-rank adapters; “QLoRA” ( Dettmers et al., 2023 ) denotes LoRA on a 4-bit quantized base model, used at P2-S1.
Benchmark
P0
P1
P2
P3
P1 → P3
GSM8K
58.5
64.3
73.8
71.6
59.6
EDINET earnings †
0.524
0.457
0.500
0.488
0.491
EDINET fraud †
0.516
0.554
0.534
0.614
0.499
EDINET industry
4.7
8.7
7.9
8.2
10.4
JP Fin Harness
45.0
53.5
31.6
49.6
56.2
Table 2: Evaluation against the un-fine-tuned baseline (P0), after each training phase (P1–P3), and for the skip-P2 ablation (P1 → P3). † ROC-AUC; other metrics are Accuracy. Bold marks the best score per row. EDINET earnings is near-chance for all our checkpoints (ROC-AUC ≈ 0.46–0.52), so the bold entry in that row is the numerical maximum, not a meaningful capability difference. Scores are single greedy runs; see Table 9 for multi-seed means.
Appendix figures & tables13 assets
Supplementary material from the paper’s appendix.
Appendix
Figure 1: Architecture of the proposed model. The input image is connected to the language model through SigLIP-v2 and the MLP projector, and is processed jointly with the input text. By reading document pages directly as images, the model generates output text while preserving layout information such as tables, body text, and numerical arrangements.
Figure 2: Overview of the three-phase staged continual adaptation pipeline. Phase 1 (Vision-Language Alignment) : P1-S1 trains only the projector on STAIR Captions and government-PDF OCR (vision encoder and LLM frozen); P1-S2 fine-tunes all three components (vision, projector, LLM via LoRA) on Visual QA and JA-VG-VQA. Phase 2 (Mathematical Reasoning Distillation) : P2-S1 updates the LLM via QLoRA on approximately 150K math problems with XML-structured chain-of-thought supervision from Qwen3-30B-A3B-Thinking-2507 (vision encoder and projector frozen). Phase 3 (Financial-Domain Adaptation) : P3-S1 adapts the LLM to text-only financial benchmarks (FinQA, ConvFinQA, TAT-QA); P3-S2 then trains the projector together with LoRA adapters on the LLM using visual financial QA from government PDFs (vision encoder frozen throughout P3). Flame icons indicate trainable modules; snowflake icons indicate frozen modules.
Phase
Type
Content
Examples
Type total
P1-S1
OCR / Caption
STAIR Captions ( Yoshikawa et al., 2017 )
820,310
1,084,952
OCR data from government PDFs (synthesised)
264,642
P1-S2
VQA
Extractive + reasoning QA from government PDFs (synthesised)
264,642
365,137
JA-VG-VQA conversational ( LLM-jp, 2024 )
99,995
JA-VG-VQA-500 ( SakanaAI, 2024 )
500
P2-S1
Reasoning SFT
sbintuitions/MGSM_ja ( SB Intuitions, 2024 )
250
∼ 150,000
Appendix
Table 3: Datasets used for training at each phase, with per-dataset sample counts and per-type subtotals. “Examples” counts captions for STAIR, image–QA pairs for VQA-style data, and problem–solution pairs for math/financial QA. Public-dataset counts are taken from the train splits of the original releases; the math corpus is a random sample of 150K problems drawn across the six listed sources (each entry shows the source’s total available size). The datasets constructed in this work (synthesised from government PDFs) are publicly released on the Hugging Face Hub (Appendix B ).
Phase
LR
Batch
LoRA (r,α)
Epochs
P1-S1
1e-3
2
None
2
P1-S2
2e-5
2
64, 128
1
P1-S2B (LLM)
1e-5
2
64, 128
1
P1-S2B (Vision)
2e-6
2
64, 128
1
P2-S1 (SFT, QLoRA)
2e-4
2
32, 64
1
P3-S1 / P3-S2
5e-6
2
16, 32
3
Appendix
Table 4: Main training hyperparameters by stage. “P1-S2” is the primary projector-and-vision-update sub-step; “P1-S2B (LLM/Vision)” denotes the subsequent step where the LLM is adapted with LoRA using per-module learning rates. “P2-S1 (SFT)” lists the hyperparameters of the chain-of-thought supervised distillation sub-phase; this stage uses QLoRA (4-bit NF4 quantized base with LoRA adapters), whereas all other stages use full-precision LoRA. P3-S2 shares the P3-S1 configuration unless otherwise noted.
JP Fin task
P0
P1
P2
P3-1
P3-2
P1 → P3
chabsa
0.8591
0.9428
0.5814
0.9357
0.9353
0.9479
cma_basics
0.3421
0.5526
0.2105
0.3947
0.3947
0.5789
cpa_audit
0.2764
0.2236
0.1683
0.2487
0.2513
0.2312
fp2
0.2989
0.3432
0.1789
0.2863
0.3011
0.3832
security_sales_1
0.4737
0.6140
0.4386
0.5614
0.5965
0.6667
Average
0.4500
0.5352
0.3155
0.4854
0.4958
0.5616
Appendix
Table 5: Breakdown on JP Fin Harness tasks (Accuracy). P0 is the un-fine-tuned baseline; P3-1 / P3-2 are the two sub-stages of Phase 3; P1 → P3 is the skip-P2 ablation. Bold indicates the best-performing model for each task.
Benchmark
Llama-3.3-70B
GPT-5
DeepSeek-R1
Ours (P3)
EDINET earnings †
0.41
0.62
0.46
0.488
EDINET fraud †
0.59
0.62
0.56
0.614
EDINET industry
14.0
31.0
16.0
8.2
Appendix
Table 6: EDINET comparison. All scores use the EDINET-Bench text-input setting in which the financial statements (Summary, balance sheet, profit-and-loss, and cash-flow tables) are supplied to the LLM as text rather than page images; the vision modality is not exercised by this benchmark. The Llama-3.3-70B ( Meta, 2024 ) , GPT-5, and DeepSeek-R1 numbers are the Summary+BS+CF+PL rows of EDINET-Bench ( Sugiura et al., 2026 ) Table 6 (means over three runs), i.e. the same input setup as ours, and are listed for context only, since cross-source comparisons are indicative rather than head-to-head. † ROC-AUC; industry is Accuracy. Bold marks the best score per row.
Model
Size
Avg.
Claude 3.5 Sonnet ( Anthropic, 2024 )
proprietary
77.0
Qwen2-72B-Instruct ( Qwen Team, 2024 )
72B
67.7
Qwen-14B-Chat ( Qwen Team, 2023 )
14B
49.1
Meta-Llama-3-8B-Instruct ( Grattafiori et al., 2024 )
8B
44.7
Ours (P0)
8B
45.0
Ours (P1)
8B
53.5
Appendix
Table 7: JP Fin Harness comparison. External scores are from the official 0-shot leaderboard ( Hirano, 2023 ) . Ours (P0) is the un-fine-tuned llm-jp-4-8B-Instruct baseline; we additionally show Ours (P1), Ours (P1 → P3), and Ours (P3) because JP Fin Harness peaks at P1 → P3. Bold: best score.
Benchmark
Qwen-14B Chat
Qwen3 8B-base
Llama 3 8B
Ours (P0)
Ours (P1)
Ours (P2)
Ours (P3)
GSM8K
59.3
89.84
84.5
58.5
64.3
73.8
71.6
Appendix
Table 8: GSM8K accuracy comparison with external models and our four checkpoints (P0–P3). Qwen-14B Chat ( Qwen Team, 2023 ) was evaluated in our setting; Qwen3 8B-base ( Qwen Team, 2025a ) and Llama 3 8B ( Grattafiori et al., 2024 ) results are taken from their respective technical reports (both base-model values). Ours (P0) is the un-fine-tuned llm-jp-4-8B-Instruct baseline. Our Phase 2/3 checkpoints are evaluated on the GSM8K test split after distillation on a 150K-problem mix randomly sampled from MathInstruct, OpenMathReasoning, OpenR1-Math-220k, orca-math-word-problems-200k, NuminaMath-1.5, and MGSM-ja; some of these aggregate corpora include GSM8K-style problems, so the comparison should be read with this in-distribution fine-tuning in mind. Where GSM8K-derived problems appear in the training mix, they originate solely from the GSM8K train split; the GSM8K test split used here for evaluation is held out and never enters P2 distillation, so the reported gains are not attributable to test-set leakage. Bold indicates the highest score.
Benchmark
P1
P2
P3
GSM8K
62.6±0.5
69.4±1.4
68.8±1.3
EDINET earnings †
0.475±0.014
0.484±0.025
0.473±0.025
EDINET fraud †
0.562±0.008
0.523±0.008
0.547±0.005
EDINET industry
6.7±0.4
6.8±0.3
6.0±0.4
JP Fin chabsa
0.909±0.001
0.587±0.001
0.924±0.001
JP Fin cma_basics
0.500±0.021
0.219±0.012
0.360±0.106
Appendix
Table 9: Multi-seed robustness evaluation (temperature 0.7, top_p 0.95, 3 seeds). Values are mean ± standard deviation. GSM8K and JP Fin Harness subtasks are Accuracy; EDINET metrics are ROC-AUC ( † ) or Accuracy.
Figure 4: Loss curves during three-stage training. Phase 1 achieves vision–language alignment, Phase 2 develops reasoning, and Phase 3 performs financial adaptation in sequence.