Crickey I'm forever changing lenses without switching the camera off and I'm sure masses of wedding photographers don't. I've noticed that if in live view the camera switches out of that mode as soon as you begin to detach the lens. (Losing contact with the communication pins). This is with the 5D series,, so I'd have thought that with the R5 it would drop the shutter. Hell, even the end caps don't go on the lenses, just into the bag as they are. If doing this with an R5 caused problems to the camera I think that would be a big issue for the likes of wedding photographers. Have to admit I hadn't thought about the issue of IS not parking up, if indeed it does.It would have never occurred to me to remove a lens while the camera is still on. It’s not like I’m going to shoot anything without a lens on, or something.