We tested models with knowledge cutoffs in 2025 so expect them to have knowledge of Tax Year 2024 forms in their weights. We also tested models with ability to do web search to get any other forms it thinks necessary: https://github.com/column-tax/tax-calc-bench
That all being said, we agree, which is what we've built with our internal tax coding agent, Iris: https://www.columntax.com/blog/introducing-iris-our-ai-tax-d... (ability to get just the right Tax form context on a per-line basis to turn the tax law into code).