Sooo, it seems it may be confession time. The sanded XHP-70 in the maglite is running strong with no hint of degradation or other harm to the dome. The four XHP 50's I sanded went into a quad light (build thread in the near future). I finished the light around midnight and rushed to test it out. Amp draw on a pair of powerizer 26650s was 15 amps.
After amazing myself with the wall of light for a minute or two I went back inside and happened to look at the domes. Two of the domes had black carbonized tunnels in them from the apex almost down to the phosphor. They like very symmetrical mini volcanoes. The third dome had cracks in the surface like old leather and the fourth was perfect. Yes, I completely forgot to wash down the domes after sanding. I expect some particles from the sandpaper remained on some of the domes and burned their way down into the dome material.
After care included dome shaving and polishing for all four emitters followed by thorough cleaning with alcohol. I probably shouldn't have used alcohol but aside from some smoking for a while on turbo I seem to have gotten away with it. The beam is still clear of artifacts with OP reflectors and much more pleasing than the domed emitters were with the reflectors I'm using. I doubt any more dome sanding is in my future since the shaving seems pretty easy and is perhaps a bit less risky.
