Google is unclear. I think I have read somewhere in here that the cassette spacing is the same so the mechs are interchangeable with cassettes but can’t find it.

I’m going to say yes but I’m not speaking from a position of true knowledge.  I know that plenty of people (me included) are using Sram mech with a Shimano 11spd cassette due to not wanting to switch to XD driver or pre GX 11spd so in theory it’d work the other way as well……

Yes 11 speed Shimano and Sram casettes are interchangeable so long as you swap the driver .

Yes on a 1×11 the xt di2 mech work on a sram 10-42 xd casttette just fine

Have been running sram 10-42 cassette and chain on xt  di2, not a problem , plus seem to get a better chainline from the xd cassette than on the Shimano one I was running.

Great, thanks all.