I gave the FXQ50 a whirl
You can use the trail scope mounts on the core and just put the lens needed on the back of the clip-on unit. It came out a little high for a standard ar mount but would zero fine still. I believe off top of head it was around 1.7" high. It still zeroed fine just didn't look like it was lined up to me.
The objective mount lines it up perfectly, but had some flex in it so when you push buttons or side focus you may push it off allotment a little.
The unit works best with something 2x on bottom so you can see all the settings and menu options while it's on the scope.
I'd say it works best up to around 5-6x on the scope. I've shot it on 10x but I'm just not sure I was gaining anything at that point vs staying on 5x due to loss of resolution.