New MX 525GB Windows 10 64-bit, drive migrated system nonproblem. Turned on Momentum Cache and system stays at Restarting for at least an hour. I hard reset the system and upon reboot, the Start Menu was corrupt according to Windows 10 Critical Error.
It shouldn't really take any longer at all. It's just a reboot so the service can begin on system start or something. It's not 'doing anything' so to speak that you'd especially have to wait for.
Note: the nature of RAM caching software is that a crash has the potential to be hazardous to your data. This is why it insists you have a UPS to use it. So you were pretty unlucky to get one whilst enabling it.
Personally I don't use it. I'm sure 99.9% of the time people are going to be fine. But if there wasn't a slight risk assosciated with an unexpected shutdown - there wouldn't be that insistance upon a UPS... That's my view.