Super fascinating!! Verification is SUPER important I think.
I actually wrote an FOSS end-to-end TensorFlow CNN accelerator that can be synthesized for FPGAs using completely FOSS tools.
I'm working on adding formal verification to it. I used FOSS tools such as Yosys and NextPNR, made possible by FOSS hackers who reverse engineered different FPGAs.
I hope to release the full codebase at the end of this summer. https://bracketmaster.github.io/MAERI-RTL/
I also started a company working on a completely FOSS CPU+GPU using similar approaches. https://systemeslibres.org