Thank you Tom Tom. The link you gave for silicone ring appears to be much cheaper (but same idea) as toddcshoe’s suggestion of the Surefire add on in earlier thread post.

For those who are interested, my measurement with digital calipers of diameters are (three measurement average)
tube where knurling is at: 25.0mm
screw on tailcap: 29.6mm
aluminum factory grip ring 35.0mm (important to know as it rolls now with this so any addition needs to be larger diameter and not perfectly round to prevent roll).
mildly stretched diameter of factory holster for Olight M3XS-UT is 38.5mm

Since my OP, so far my own best hack job idea (not as ugly as original idea grip tape) for anti-roll addition is this:
Though the anodized aluminum grip ring there is a hole. Thread through this hole store bought polymer cable tie. The ones I have are 7.1 inches (181mm) length and cost about $5 for 50 ties. With this cable tie on the M3XS-UT can still fit into the factory holster. Please see photograph.