Avaliado com 4 de 5 estrelas

Working great in 78.9.0 but where do I find the preferences tab to choose custom shortcuts? I'm lost.

Esta análise é para uma versão anterior do extra (1.7). 

You need the "Manage Extension Shortcuts" tab.
It can be found via menu: Tools, Add-ons and Themes, click on the wheel up right and you'll find: Manage Extension Shortcuts.

Sorry for my very late reply, hope you found it in the mean time.