I’ll probably send the unit back to Bryston to have a SSD installed ... My thought is that having an internal SSD installed means that I could potentially loose all of those files, for example in doing a factory reset.
Bryston or your dealer can install the SSD for you but it’s not difficult to DIY. The BDP-3 system files are independent of the SSD, so you can do a system reset without affecting your files. I wouldn’t provide you that assurance without personal experience.