AR, KY, KS, and OK should utilize the power of their state supreme courts to reverse gerrymandering, no?
AR is a Dem map. They could've gerrymandered a single D district but were too confident they could hold up against trends.
KY has some pretty strong anti-gerrymandering rules in its constitution and the Democrats held the Governorship and State House when the map was drawn anyway. Tough to see how things get better than the current map, you could shift some counties in KY-06 around but that would probably violate the state constitution. That also protects Louisville from being split, so Kentucky will be locked into a 5-1 map for quite some time.
Kansas was actually court drawn because the GOP in the legislature couldn't stop infighting. KS-03 could have Lawrence returned to it to boost it but that'd be more of a Dem gerrymander than removal of a current one. Plus KS-02 was close with it last time but can't really be made stronger. Not much else that can be done there.
Oklahoma in theory could have Kendra Horn put in a better position by removing the rural counties and replacing it with the part of Oklahoma County cut out, but even then she'd be quite the underdog. And no way to make the map more D-friendly. The Oklahoma County split is the only real gerrymander in it anyway.