I don't want to add any extra hassle to getting the next update out, but...
In version 3.6, it seems that the stone slab alt is the cobblestone slab texture. Is it possible that you could make a different alt that's more in line with the stone slab itself? I think it would make that block a little more useful since it could be its own distinct slab. Moreover, the cobblestone slabs are already an option and whatnot, so the stone slab probably deserves some sort of unique alt.
Hope it's not an extra bother for you.
EDIT: Okay, looking at the textures, it looks like the stone slab already has alternate top textures, but I'm not sure which file is contributing to the cobblestone alt.
Hi! Just wanted to say my friends and I have been using your pack for actual literal years (personally, I think I've been using pixel perfection since... at LEAST 1.7.2). We really appreciate your work and have been trying to temporarily find another pack until pixel perfection updates, but none of them come close!! The color palette and textures are amazing. Thanks for all of your hard work for all these years!!! We are all really excited for the next update for 1.13!