Yep I am a rifle shooter as well
The principals are totally different. In a rifle scope the image of the sighting reference be it a dot or cross hair is magnified, therefore there is an associated focal length. In these sights the aiming refrence and your eye are seperated by a lens. Therfore any time you change the distance between your eye and the scope the amount of magnification changes as does the aiming refrence (dot or cross hair) size.
With a reflector sight there is no magnification whatsoever on the displayed reticle. There is no lens between your eye and the projected reticle. The reticle is displayed at infinity. I have used slightly more advanced gyro reflector sights in real life ... Ferranti Isis and CSF97K and HUDs,though more modern than the Revis the basic principals are the same. The symbology size does not change as you move your eyes closer or further from the combining glass. If it did than any form of angular range finding (stadimetric) would not be possible.