I would gerneally advise against additional orbital infrastructure as:
1. The AI already does not utilize anything beyond fuel depots and other already existing options already serve as player exclusice advantages when utilized and if the AI is optimited I woudl prefer it to be done on making positioning smarter and more efficient instead of for new features
2. Managing various types of outposts is a micro MGMT intensive activity: building various types and sending them ot the correct systems, and deplyoing them indivudally
3. The already existing options of reasearch stations and habitats already give a miniscule advantage to not make the micro realy worth it - the focus of the game should rather fall onto the tactical combat and fleet positioning
That being said I agree that there are way to many planetss lying around just begging to be done something with.
Setting up manual mining operations, habitats, resarch bases is probably not the most elegant way of going abouth it: compare the current system with that of stellaris, where the cosntruction ships can be ordered to build extraction bases for all the planets within the system with 3 clicks - SiS mechanic is simply not fit for this (1. analysis which planets are availabel and what to build, 2. issue build orders, 3. wait for ships to finish (and remembe what for), 4. issue target system to each ship 5. issue deployement orders for each ship, 6: optional: embark pop to habitat
) - Occasional range extending outposts for strategic purposes are fine but the player shoudl not feel that each planet is a dangling carrot that shoudl be farmed or loose out on benefits
So instead, lets reduce the number of planets in a system or have the benefit of some special planets apply automatically to other colonised planets within the system - this can be tied to research if that makes sense. e.g.: gas giants provide reasearch bonus to all colonised planets within the system but only if specific tech has been researched