Hi, thanks for the review. I've filed a bug (#1418984) requesting the ability to set locale-specific shortcuts while the bigger shortcut customization work is done. Assuming that gets implemented, what would be a good default on a German keyboard? You can comment here, send me an email, or respond to my tracking issue for the addon here: https://github.com/thePaulV/Most-Recent-Tab/issues/4

Update: Version 2.0 lets you set your own shortcut