I’ve made some changes that will take effect with the next beta build. Currently the plugin will not load if it has expired, which means you cannot get to the About Box to download an update. In the future, expired betas will still load. Also to come, when you check for an update in a beta version, the dialog will read something like “Alt-click Get Update to download the release version instead of beta.”
Would it be helpful to add an undocumented behavior where Alt/Option clicking the Get Update button in a release version will fetch the beta version instead?