Hi,
First of all, I'm not against addition of this "select scoped talloc context", and it's fine for me to merge if others find it's a really handy feature. But I have the feeling it really adds unneeded extra complexity and scenarios to take care in the code. New ways to get shot on your knee, having to use talloc_steal() and talloc_reparent(). Not sure if the benefits are worth the effort and increase of complexity.
IMHO we should be fine using regular global context (and freeing stuff around) together with static/stack buffers when possible.
Regards, Pau