I believe you’re right that popping the bubbles would help, but imo it makes more sense to simply manage your vacuum so that more of the slab stays in contact with the tray…which is where the heat is.
Will the 441.6 nm or 458 and 488 nm light wreck you extract? Dunno. given the current state of cannabinoid analytical methods, it would have to be fairly dramatic for you to notice it. It might still be problematic.
