Or maybe you can solve it like I did -- by using a font that does the (IMHO) right thing with regards to ligatures

https://github.com/0xType/0xProto#4-ligatures-that-dont-defo...

I can't recommend 0xProto enough, the only thing I'm sorry about is that I didn't find it sooner :)

Going to give this one a try; I'm still partial to Atkinson hyper legible, but this one looks fun.