How much current are you driving it at? I would personally add a note of caution to this.
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Instance #1:
In my XHP70 DST, I also wanted to get rid of as much of the artifacts/donut as I could, but I didn’t want to mess with my beautiful smooth reflector (in case I want to go back to thrower later). First I shaved/sliced down the dome (the dome magnifies the emitter, and it also magnifies the gap between the dies). Then I very lightly sanded the flat top with 800 grit wet/dry, and cleaned it off with some isopropyl. It ended up with a very nice frosted effect. I fired it up with a FET driver at around 8amps, and it was almost ruined. Apparently the frosting caused a lot of internal reflection resulting in heat. Read more about it here: Just toasted an XHP70... How can I avoid doing it again?
Instance #2:
When I was building my triple XHP-50 Fandyfire G36, I wanted the same things as my DST, so I shaved the emitters down again. This time I did not sand them. On one of them my shave job wasn’t great. It was a little uneven, but still for the most part clear so I figured it would be fine. Also driven by a FET, it smoked out just like the sanded XHP70 did. This time it killed two of the 4 dies in the process.