I believe the removal of it is both planetary fires, and realism which is essentially lore yea as after all it is a bit silly to have Chlorine-Tritium-heilium-3 atmospheres, and maybe a bit of balance though that is more a issue of how it works, I personally would be really open to this, as it opens yet another type of place for awaysites and resource extraction, perhaps very very minimal phoron atmospheres could be added to these on a very very rare chance too though on that end, lore likely prevents it.
In terms of ground mapping, a dedicated turf could be created, it would likely need to be a fairly dangerous place, maybe lattice could be used but not as expansively as in space? could be a bit too difficult to code limits there though.
I'm not batra who made the PR though, so don't quote me on those reasons for removal.