Just stumbled over this topic after having issues after upgrading to 2.3.10 (stable).
Some of the plugins used on our sites recently were upgraded to be compatible to more recent versions of discourse (e.g. discourse-assign). This upgrade seemed to have negative impact.
Just have changed the plugin installation to refer to stable branches of the plugins. Unfortunately not every plugin knows a stable branch. That’s an additional inconsistency within the Discourse eco system.
I do not even know if my change would have any positive impact to the Discourse installation.
Yes, please, defining stable branches within Discourse itself and all plugins would help to make it more stable. Beforehand there must be a clear definition of “stability” though 
Following this approach cannot be an option:
“Just a note that the people who maintain the software claim that the beta branch is more reliable than stable.”