Some observations ..
(a) (catchup) - you might like to revisit your contention that V1 ties in with Vmca - refer
FAR 25.107 for details
(b) the sensible way to test Vmcg is dead calm for repeatability. The Brit strategy to reduce Vmcg to 7kt crosswind conditions is laudable, but increases the certification workload, cost and difficulty for little, or no, realworld advantage ?
(c) as is regularly discussed in this forum, however, there is a quite reasonable need for crew to have an idea of the crosswind effect on Vmcg so that sensible risk minimisation strategies can be put into place for very low weight takeoffs in aircraft which are Vmcg-limited.