Since my OP, I have continued to find ways to make the M3XS-UT have anti-roll. As stated in OP, I realize these are not true mods like other ones in this forum topic. But I did not know which forum was best.

Besides the above posts suggestions (all of which have advantage each can be on all the time), I had and inadvertent discovery. After receiving order of Olight OEM 63mm diameter filters (white and green) , I see both have a lanyard tab with hole that will also serve as an anti-roll device. Of course the filters cannot be on the flashlight all the time as each gives significant loss of throw distance. But still good to know for those (like me) who were unaware.
In the link, one can see the lanyard tab with hole.
Olight OEM filters for M3XS-UT

So for now my anti-roll devices are:

  • 7.1inch (181mm) polymer cable tie through the grip ring hole (b.c. most cheap)
  • Olight OEM 63mm filter: but cannot have on all time as defeats primary design purpose of light

The Surefire rings look the most “professional” and are priced accordingly. Aargh. And search continues in local stores for appropriate sized low priced silicone rings.