I took a couple test shots at my lowest fireable power and included it in the photo below. They don’t burn through (saving your mirrors), and they make a big, clear thermal mark with a little bubbling at the exact point of impact. This combo should give you great visibility at a distance as well as accurate enough detail up close.
They stick really well, so they won’t fall off during testing either. Get em while they’re cheap.
Note: Because the adhesive on these is so good, there’s no need to stick them on too heavily, unless you enjoy Goo Gone’ing your mirror mounts. As sticky as they are, they come off easily if they aren’t left on for a long time.