I've never liked the optimization tag. I would like to see it burninated and replaced by three tags:
speed-optimization, synonymized to performance
A question that asks for "optimization" in general doesn't have focus, and doesn't need any of those tags at all.
This reorganization would also pave the way for the ...
There's no option for users to migrate from meta to main, because that only ever happens once in a blue moon - there's theoretically no solid grounds to enable that migration path.
The current way to migrate from meta to main, is to custom-flag for moderator attention.
Looking at migration stats for meta (are those accessible with 10K privs?), looking at ...