On Windows using the standard install, profiles for Alpha and Release (stable) are in the same location

According to @pierov they should be located in a different folder.

This can be an issue, because opening a profile in a later release is not-backward compatible. If you open a stable release profile in alpha, you can't open it again from the stable.

(Also, firefox is introducing a profile switcher in the coming year, that you can now try in the nightly channel)

CC @bella @morgan (this is a blocker to make public the alpha channel, which we want to do as soon as possible)