It doesn't quite fit under either, but a bit overlapping—I think a huge help would be the ability to "withdraw" liquidity". I've started to experiment with giving markets some more liquidity and setting closing times so that's affordable, and for e.g. an election it's a shame to tell people "no more trading after this point". Ideally I'd just say "Ok I'm only funding the full liquidity while it's uncertain", and as results roll in traders can continue to trade without it costing me a ton.
Retroactive partial/NA is more broad—it also works for cases that you don't know what the closing time should be, which is cool ("will X happen during June"). but I feel like withdrawing liquidity is lower hanging fruit, because retroactive partial N/A has a lot of other challenges. e.g. creators are bound to underspecify it, and traders will find it veeeery frustrating when creators suddenly roll back their trades without being properly warned. doable, but i expect it'll be a very common point of friction