Anyone familiar with the Paul sram shift adapter? I want to build a gravel bike with low gearing (sub 20 gear inches) since the grx and Sram 1x drivetrains I see on complete bikes don't have what I want.

Found this adapter to mount a sram mtb shifter to 31.8mm drop bars:
https://www.paulcomp.com/shop/components/drivetrain/shifting/sram-shifter-adaptor/

Has anyone built a bike around this? I want to use a sram nx 1x12 drivetrain, and am wondering how to make sure it will work with the frame I pick (either Jamis Escapade or Niner rlt 9 RDO). Would the nx 12 speed cassette work on 11 speed wheels? I understand it doesn't use the XD driver.

Any help would be appreciated.

Dave