Hi! I’m not familiar with specifics of Tumbleweed and beta software, but in general, the perfect state would be creating a dedicated OS installation on a separate hard drive, just for testing. That way, you get the safety of not installing anything over top of your existing system, and the testing accuracy of using your real, “bare metal” hardware.
If that’s not an option, a virtual machine can get you the relative safety, although it won’t as accurately reflect performance with your hardware. Dual-booting on a single drive is also an option, although partitioning always freaks me out 
I would caution that, as far as I remember and understand it, the default configuration for snapshots in Tumbleweed covers system software, but not your own home directory files - so it seems like there’d be some risk in relying on a snapper rollback if you need to recover from a beta issue.