If anyone is interested, The glock RMR mos screws will work to mount the RMR to the Echelon. SA says the screws can protrude no longer than .110 out the bottom. So for me, with the RMR type 2 adjustable and no base or seal plate (not needed), I needed a 6 32 no longer than .390 screw. That‘s about 3/8ths (.375). The Glock mos RMR screws that came with a seal plate I had on hand were .380. They worked fine.
The Trijicon RMR short screw set will work also if want to pay $15. You can also cut the 1/2 inch 6 32 screws that come with the RMR or use an appropriate 6 32 3/8 screw.
Would it kill Trijicon to ship the regular AND short screw set with the $400 + RMR?
These are the screws I had and used:

The Trijicon RMR short screw set will work also if want to pay $15. You can also cut the 1/2 inch 6 32 screws that come with the RMR or use an appropriate 6 32 3/8 screw.
Would it kill Trijicon to ship the regular AND short screw set with the $400 + RMR?
These are the screws I had and used:
