Glock GR43 Recover Rail

Q: The add says injected molded glass reinforced nylon. one of the reviews says 3d printed. it can't be both. which is correct?

The reviewer has no idea what he is talking about since he is not the manufacturer. It is glass injected nylon, same as Sig P365 frame.

Q: Has anyone tried using this to attach a Mantis X shooting aid?

Mantis x can be mounted on the magazine plate to any pistol

Q: Would this be compatible with .45 shield 2.0

To my understanding the .45ACP slight slightly larger/thicker. Things made for the 9MM/.40SW may fit, but may require modification and it is not recommended. If they made one for the 45, I would buy one too.

Q: Will it fit my 365 XL

It should, but mine is a standard so I can't say for sure. If you grip module has the same Sig propietary rail as the standard just longer it should fit. You may have to do some filing on one of the rail lugs dependent on where you want your accessory to mount. I needed the laser switch closer to the trigger guard than the lugs would allow so I used a small round file to put a groove in one of the lugs for the laser's screw to pass through. I have a LaserMax mini green laser, others may not be an issue.