So if you updated to OTA5 on RC channel, you can go back to OTA4 on stable.
But once released on stable there is no coming back except if you saved the system.img files so you can manually go back.

That's why it's important to have as many testers as possible for a release candidate versions.
So the release could be stopped in case of a blocking point.

But in this case, an issue with a specific application on Waydroid will not qualify as a blocking point, but at least people would know before the stable release.