Huge fan of Town Portal. They’re great live as well. They’ve got a raw edge which separates them from most math rock, which can sometimes seem impressive but emotionally cold (as was some prog back in the day).
Not necessarily my favourite instrumental band, but Knife The Glitter released an album a few years ago. One of them used to be a DEP guitarist, and it’s some brilliant instrumental mathcore with interesting instrumental flourishes.
Hard to count them as a full instrumental band since they just play acoustic guitars but I do enjoy a bit of Rodrigo y Gabriela, though not sure they ever reached the heights of Tamacun or Diablo Rojo again.
Also, jazz. Jazz comes in so many forms, I find jazz singers the hardest to get on board with, so most if what I listen to in the genre is instrumental. There’s no end of great instrumental jazz, but not to divert too far from the brief, try Sons of Kemet for something propulsive and banging: