I would first turn it into a properly synced and serialized entity component on the planet, rather than the mix of session and planet components it is now. Also, I would introduce connected-claims where you can pay tax on the whole connected set of claims rather than go block-by-block. Finally, I would introduce, through the diplomacy system, a mechanic for people to trade or war over claims. Though the latter is a bit more complicated process because it would start to tie into what is a war
But the first two things definitely.
There are too many desync problems with the current implementation
And having to go block-by-block to pay taxes is a pain I never enjoyed
It came from a design point of view where the designer was expecting people to claim 1, maybe 2 areas, and that's it
Everything at the time was designed to prevent people from building larger constructions
Also there are problems with how the claimable areas are distributed over planet surface, especially re: larger planets