I’m from the Uk so obviously the Australian climate is much different
In my opinion the neck should never feel tight in the pocket. You shouldn’t need to apply pressure to get it to fit, but at the same time there shouldn’t really be any perceptible gaps when it is bolted together. Thats why we build for ourselves, as you’ve alluded already, the mass produced guitars sometimes don’t meet our standards.
I had a similar issue with my last guitar on the next pocket, I made up a veneer and glued it in place, now there are no gaps and the veneer can’t be seen by the naked eye. The neck doesn’t feel ‘tight’ but fits like a glove.i think that should provide enough space for wood expansion.
hope that helps