Hi guys, I’ve searched this forum and google and can’t find anything about cutting stamp rubber. Specifically, I was wondering if there is a setting or technique to get a chamfer on the edge on the engraving. The laser was advertised as being able to make stamps and even came with Winsealxp so I just assumed being able to chamfer the engravings would be doable since this is common with stamp making.
Laser shoots straight down. There will be no chamfer done unless you want to redesign the head to point the beam at an angle for you.
You can chamfer with a very dialed in smoothie or DSP a lots of tests. This is done via greyscale
He said “dialed in” … 1-800-2SMOOTH. 
One thing you might want to try on a ruined stamp to see if it works is to play a propane torch across the face quickly. The sharp edges will burn/melt away.(theoretically)
This sort of process in used in manufacturing a variety of cut goods which can’t be tumbled or blasted. ‘Flame deburring’ it’s known as.
I can’t promise it will work, but it’s where I’d start.
Good luck
Scott