For the abilities, Filter and Tinted Lens, the effectiveness checks only compare against 2x and 4x (or 0.5x and 0.25x for Lens). This is enough for almost all circumstances, but it is possible to set up battles where they should trigger but don't.

For Filter, you can use Smeargle to move Filter onto a Scizor, then use Forest's Curse on it. At that point, any Fire attack will be 8x super effective, bypassing Filter's damage reduction (though probably still killing).

For Tinted Lens, a Kingdra with Forest's Curse can be targeted by a Water move (HP-Water on HA Butterfree?) for a 8x resist, but Tinted Lens doesn't boost the damage.

Recommend changing the checks to >= 2D and <=0.5D respectively, like the other effectiveness checks.