Since the game are very narrow minded in colony developments I would suggest one rather simple change.

Make negative maintenance from planetary structures three of four times more expensive. This will force you to make a hard decision on your focus and also more realistic at the same time. If you can support the infrastructure locally maintenance become cheaper but you will have to trade some efficiency in industry or research for doing so.

This would also improve the importance of having a good economy and not just try to make sure you stay afloat but really invest in trade and tourism to support growing forge worlds.

Example...

A world has a maintenance cost of 5 and produce 2.5 credits locally, that -2.5 credits would now instead cost you 10 credits from your overall empire balance sheet. If you increased the income on the planet by 1.5 credit you only pay 4 credits from the empire balance sheet.

This would at least force you to think hard about your economy and how to develop it in order to really support super specialized worlds properly.