When I think about it it's not even that hard. Maybe give us some unique power (like the tadpole powers) in exchange for a paremant disability (remove ability point, give something like with the deal with the hag etc)

Larian's Biggest Oversight, what to do about it, and My personal review of BG3 EA
"74.85% of you stood with the Tieflings, and 25.15% of you sided with Minthara. Good outweighs evil, it seems."