This has always been helpful, now seems about essential.
The one I just worked on in my other reply has the regular old W11 on one partition and the clean new carefully prepared W10 on the other partition of the same chip-based SSD. Page File (swap file) and hibernation have been disabled, these are not needed since there is plenty of memory and it's a low-energy desktop PC.
When you boot from a cold start the UEFI firmware takes a couple more seconds since the extra partition is there, but after that W10 pops up in less than 20 seconds. It's not a very powerful PC, a bit below mid-consumer range, and it's a SATA version not nvme.
It's just not really painful at all to reboot between W10 and W11 whenever you want to.
The advantage is like having two different PCs, which is also the disadvantage because you have to install two OS's for real.
If I was a gamer I would want at least one OS to be that way, optimized but not exactly for WFH.
