Would you mind sharing some tips on how to set that up? A code snippet or a link to the relevant docs would be super helpful.

Certainly, the bulk of the functionality is provided by URLDispatcher:

https://www.hammerspoon.org/Spoons/URLDispatcher.html

Here's a cleaned up version of my config... I also mapped global cmd-shift-1/2/i to focus my profile and incognito windows (and create a window if none already existed):

https://gist.github.com/beaugunderson/d1ca2218b9b272f3ac3573...