For me, the interesting parts of Stripe's description of BYOT are the size limit 2-5 and the acknowledgement that it is an experiment. The size because of the current top comment to the question describes a larger team and the problem of pruning for needs and Stripe more or less shifts pruning to the team. The experiment because it seems directly drawn from YC's language regarding new programs -- maybe it will work and we'll try it out and see.
I even have some team members in mind ...