the setting "enable experimental updates" is not set when you download an experimental Version (f.e. as zip). So when I read that there is a new Version out, I go into my game About->CheckForUpdates and got "No Updates availiable".
So I've two suggestions:
- Enable Experimental Updates by default for experimental Versions
- Give a hint when you manually (About -> Check for Upadtes) check for updates (without experimenatls enabled) and there is a new experimental availiable. (f.e. No new stable Version availiable.\n There is a new experimenatal Version availiable, enable experimental updates to get it.)