I made a whole post about this idea, including possible formulas to balance it with the current game state. But now I'm thinking people might be tempted to do this simply because industry bases are going to be stronger with the rebalance.

Five kits per character is fine for StM but not for ExE and CA. If higher tech bases had natural bonuses to extraction and colonies (not just suitability, also caps on quantity sold per tick), it could actually make sense to use fewer, high tech kits for those tasks and I might be convinced to go with this.

The easiest way I can see to implement this is to make base kit tech give a multiplier to the effectiveness of ExE and CA owning the kit. A typical maxed SM CA alt will be laying about 15 T3 kits, I suppose, so we would need a x3 CA bonus if using 5 T20 instead. Since it's much easier to develop and manage 5 colony planets than 15 (and these five planets would have almost guaranteed max suitability), this bonus could get scaled back to maybe x2.

ExE is a little trickier since (1) it's a big penalty to only be able to extract from five sources, and (2) extraction bonuses could cause a glut in tier 3 commodities. I currently use three endgame T16 extractor kits for metals and 5 T9 kits for oats. If I could replace those by 1 T20 for metals and 2 T20 for oats, I would be content with the change (leaving me 2 more ExE slots on that character). That means that T20 ExE kits would need to receive approximately x3 effective ExE. It may sound like a lot but in the end I'd have approximately the same quantity of resources coming in at the cost of several base slots I currently use to extract other valuable stuff.

So to a first approximation I'd propose
CA multiplier up to x2 for T20 and
ExE multiplier up to x3 for T20
both starting at x1 for T3 and proportional to station slots required.

An unintended consequence of this approach is that endgame players could actually viably share galaxies. That would allow teams to condense their territory and perhaps we could convince the admins to get rid of some of those useless connector galaxies!

Why not add in tiered advanced extractors for ExE (like one requiring 15 (TL 15), one requiring 30 (tL 20))? Then we can still work with the system we have but make higher tiered bases more attractive for ExEs.

As for CA's, how about cheaper/ alternative variants of the geo projects that people currently use to up suitability that have to stay equipped on the base?

There are already T15 and T16 extractors which people do use, but nothing past that. I have never laid an ExE base above T16.

There are already T15 and T16 extractors which people do use, but nothing past that. I have never laid an ExE base above T16.