While I can only guess about the mini remote, I have a few small gadgets that I leave plugged in for long periods of time without any problems that I notice. I don't know why the mini remote would be any different. The risk, in my mind, if any, is only to the battery.
The battery photo in the FCC Database shows the battery has a small PC Board on it. It should be the batteries protection circuits. To prevent things like over current out, low voltage cutoff, over charging. Depending on how well it works and the remotes charging circuit design. It maybe all right. I am not sure if I would do it myself.