How much of current venture spending is going into reusable R&D that can be moved forward in time the way that physical infrastructure in their examples were able to be used in the future?
That... is not relevant. The question is what percentage of R&D spend gets "encoded" into something that can survive the dissolution of its holding company and how much does a transfer to a new owner depreciate it.
I'd be shocked if more than like 20% of the VC money going into it would come out the other side during such an event.