Who is “we” (in the “We are launching”) and what is the mechanism you can convince people/investors that you or the proposer of the project know how to train large scale models and can make accurate practical estimates?

I have post-trained LLMs a lot, but ultimately it's not me proving it, it's the researchers who would pitch their work.

They can pitch it however it makes sense for their work, giving milestones similar to any other crowd funding platform.