I can't think of any flails?
For what it's worth,
I believe the gnoll boss on the risen road wields with a pretty good flail.
I'm sure druids in particular would appreciate a ranged weapon
Yes, we would.
Edit:
I haven’t seen those toes of people in a while. I feel like at least in cRPG crowd they fell out of favour once casters got a way to do damage every turn through cantrips. In BG1&2 they mostly acting as “the thing your caster uses” when you don’t want them to cast spells.
I'm not a big fan of Produce Flame in that slot, as the range isn't great, iirc. Solasta created a cantrip for this purpose, though I understand if BG3 didn't. But slings seem so simple and flavorful, it'd be a shame not to have them.