This is exactly what I've been hoping to learn - I was wondering if there was a decent, laser cuttable sublimation acrylic. Nobody I asked seemed to know, but you have a similar machine to mine and are cutting it, so I think I have my answer! I'm wondering however - Would you maybe consider it to be safe cutting after sublimation? I'm working on control panels and worry about the edges around the holes marking weirdly from the gasses being released.
I have used the 11.8 square acrylic quite a bit and really like it. Couple times I also forgot to peel plastic covering off both sides. I press for 105 sec at 365 degrees, peel and place under another cool heat press. Have made a lot of game pieces and charms. And remember, don't mirror design. Tripped up there too. Also cut great on my glowforge. Just found out they have the unisub brand. Like the idea of bigger sheets when needed.
I have tried the JPP cast acrylic and didn't like the edges but subbed well. Have to try the Unisub, glad they have other sizes, thanks for the comparison!