You can but you'll need to withdraw from the Beta programme then once confirmed you'd need to connect your device to a PC running Smart Switch and downgrade through that. The downgrade will be in effect a fresh install and you'd then need to restore backups of apps etc.
Same as Juli3n says, I've found this Beta to be stable and very little issues.
In joining a Beta programme you basically sign up and acknowledge that their may be niggles, bugs, and functions that are still in development but are live in the Beta to be tested. Anything found and the community feeds back this back to aid getting a polished final release. Unless you are happy to accept some temporary niggles then joining a Beta on your daily / main device is unwise.
You could roll back to the previous OS but given there's indications of Beta updates being weekly for the next few weeks then personally I'd be more drawn to sticking with Beta, gets the updates (which may solve your issues) and then get the live release when it drops.... which i wouldn't expect to be too far away from the start of the new year.
