Latest versions of the following fonts using ligatures are known to work in IDEA 16:
- Performance degradation was reported when 'Fira Code' font was used with ligatures enabled.
- Wrong kerning for Monoid/Monoisome (especially notable on Retina screens for 'is', 'in', 'it' pairs)
- Font rasterization is different when ligatures are enabled on Mac OS
If you are aware of any other issues, please report them here.