I'd say in general that dropping 1.18 is the better option. Not because 1.18 is an old version that needs to die, but rather because I think the LTS should serve as a gap between technical changes between versions. It probably seems more likely for someone stuck on 1.19.2 to have trouble moving onto 1.19.3 if the LTS version didn't stick with it and provide updates that can help the modder in question bridge their mod to the newer version. But yeah, incredibly scuffed versioning schema from Mojang nonetheless.