Tell us your findings.I'm actually not convinced letting your mining planets grow is optimal for organics, either. Specialized worlds benefit from several stacking bonuses that make them more efficient. In my current run, I'm going to be experimenting with this to see if reducing most of my colonies down to barebones mining colonies with their growth directed towards a smaller number of large urban worlds works better than growing every planet to be large.
I doubt it's that good to specialize fully in one resource honestly. I mean if you go for all 3 resources, you get the specialization bonus from 5% to 2%, so losing 3% base production isn't a big deal. And you can easily build all 3 "enhancer buildings" on one planet.
I suppose the big benefit of full specialization is the ability to easily gene-mod the whole planet.