I'm surprised that you removed so much options from the new versions, but I guess since you can just use 1.35 since it's still available that's okay.
1.35 is superior in many respects, including ability to auto-create palettes (which is useful if you're working with larger palettes like 256 colors), different types of dithering, more built-in palettes and in new version it seems dithering doesn't work at all in small pictures. But since you do provide the old version that doesn't matter much.