Where would it be best to control an addons allowed sites?

[voipfc]

I want to control the domains accessible by addons which work on all pages by extending them with additional code which looks up a list of domains updatable by the user and disables the addon from proceeding further if the current page is not on the list.

For many addons where would be the best place in the call cycles to insert such code? I assume that there are some common calls most addons use where it would be a good idea to call such code.

eg. uBlock Origin allows the user to disable it on certain pages, so I am sure other addons can be modified to do the same.