If you want to not be bothered about add-on compatibility then use
https://addons.mozilla.org/en-US/firefox/addon/checkcompatibility/
With that installed the browser can check version numbers as much as it wants but they will all still be active. Of course, if an add-on no longer works properly with the new browser version you might have problems but, other than occasionally an add-on no longer functioning, that hasn't happened to me (as far as I have been aware).