The comforting phrase
"Foundry compatible" is meant to calm the room. It tells investors, boards, and partners that the company does not need to build a fab and that scale can follow a known manufacturing path.
That may be directionally true. It may also hide the hardest part of the company.
Compatibility is not binary. A process can look compatible at the block-diagram level and still fail at design rules, module integration, contamination controls, thermal budgets, tool availability, yield learning, test, reliability, or qualification.
What compatibility really means
A real foundry claim answers specific questions. Which foundry? Which node or process family? Which modules change? Which tools are required? Which design rules are affected? What reliability stress is required? What is the test strategy? Who owns yield learning? What is the foundry's economic incentive to support the work?
Those questions do not diminish the story. They make the story investable.
Evidence that matters
Good evidence can include a process integration plan, PDK assumptions, tool compatibility, thermal and contamination analysis, wafer results, foundry feedback, OSAT/test assumptions, and reliability path.
Early evidence does not have to be perfect. It has to be traceable. It should show which assumptions are planning proxies and what evidence will replace them.
TIGRE lens
TIGRE separates "physically possible" from "manufacturable with a business path." The decision is not whether the process can be imagined inside a fab. The decision is whether the foundry route can support a product, qualification plan, cost model, and customer commitment.