I was looking at Mozilla’s Github repo for Firefox Multi Account Containers for native keyboard shortcuts, when I stumbled upon a comment — a hacky way to launch mutli-account containers on Firefox using Mac OS’ keyboard shortcuts feature.
By default, Firefox does offer keyboard shortcuts to launch containers of your choice. The keyboard shortcut Control + . that comes natively allows one to allow open the multi-account container selector. Selecting the actual container has to be done manually using up/down arrows or using mouse.
There’s where this trick helps. Mac OS offers App Shortcuts to assign keyboard hotkeys/shortcuts to work at the app-level environment.
Launch System Preferences > Keyboard > Shortcuts > App shortcuts to enter new hotkeys/shortcuts for Firefox.
Assign the hotkey/shortcut to launch File->New Container Tab->{Container name} and you should be all set.
This is the same as accessing the container using Firefox’s menu navigation at the top.
Related: Limit your Google and Facebook activities to specific containers on Firefox
Give it a spin and you should find yourself launching containers faster than ever!