After an entire day of fiddling with MV, PIXI, TexturePacker, Crunch and Powershell, I finally managed to get DXT textures loading in RPG Maker. They work in both .DDS (uncompressed) and .CRN (crunch compression) formats.
Only downside is crunch compression is lossy, so pixel art spritesheets don't look as nice, while .DDS looks perfect but the file size is quite a bit more than optimized PNGs.
I like to think of Profile Posts as tiny homes, full of all kinds of unsuspecting suckers "future" friends.... Many of which are of course only going to be excited when a strange man in black suddenly shows up to say hi.