There was an idea circulating long time ago but never implemented - give AI a starting atmosphere converter. It should be available from the start to AI, upgradable to "normal" converters and require immense amount of time to convert atmosphere - for example 200 turns. AI constr_facil. file should have it as a first entry for all colonies. It should fix the problem that AI never scrap facilities and for example once it builds 3 mineral miners on domed medium planet it will never scrap one in favor of atm. converter.
This mod is the first one with dedicated AI tech and should take care of this problem !