In some situations, I think the availability of early silicon could be seen as "large volume". The chip manufacturer things you are interesting enough that they allow you to be one of a limited number of customers who get very advance documents, and very early silicon. Just so that you can have a device ready - hw + sw - when the manufacturer finally have a releasable stepping.

The disadvantages if that some prototypes will never be able to do some things, because the mounted processor has critical errors with no workaround. And the reference designs may not even be finalized yet.

The advantage - access to the inner circle of engineers. And the chance of an early shipping of a competitive hardware months before the competition.

I have had "early silicon", betas of rel 1.0 of compilers and such. "a very pleasant pain in the butt" is probably the best description I can use. The adavantage of having product ready by the time the chip is released for production, so you can be first is, in certain markets, a HUGE advantage.

even better, be a consultant to the chip design team. Been there, done that (no, it was not an uC)

Erik