Thank you!
I hope I will do the same great job with XHP 50.2 and 70.2. Those are a “little bit” more expensive than these 
Had to ask there, hope RelakS can share his sanding method because I gave up on it after killing a couple XHP50A emitters.
Sanding method? 
I haven’t done anything special. I put some tiny amount of water to the sand paper, and moved the LEDs back and forth on it, without much pressure.
I also have checked the progress frequently, because I did not want to end up with the bare LED base
I think that the most important is to leave enough material from the dome to sand down. Maybe tomorrow I will do the same with an XHP50.2, I will see how it turns out. If an XHP70.2 is enough to have 1mm high cut, than for sanding, maybe 1.1mm or 1.2mm will be necessary.
Probably would be wise to use a washer that is the desired thickness as a spacer. Put the MCPCB upside down over the washer so that the LED sticks through it and the washer keeps you from sanding too far. Also would keep the LED flat against the sand paper while sanding.
Almost no pressure and wet sanding
Mmmkay, so you're speaking of super O:) gentle, slow sanding. That must be a lot of sanding time, doesn't it? 
Washer, os some flat metal, which you stick to the same base where the LED is. I use washers as spacers to cut the dome to begin with 
The problem is that if a washer is big enough to stick through the LED, or to drill a nice hole in it, it is usually too thick, so I put two small washers next to the LED.
silicone is very soft and not much area to be sanded so no
XHP70.2 next gen
unfortunately on one side a bit silicone broke off
