zzconvert 1.0.3 update
Remember this feature on the feature page?
Unsupported texture dimensions are automatically scaled to nearest power-of-two size (ex: 27x65 -> 32x64, 512x512 -> 64x64).
It should actually work now. It still hasn’t been tested very thoroughly, so the best practice is to use properly-sized textures when possible. Maybe I’ll have it print a warning or pop up an annoying message box in the future, but this quick fix will do for now.