It depends on your setup

If you have a single installation, from which you run muiltiple accounts, then yes you just install the mods in the same place as for a single account (i.e. the mod installation itself is not account-specific).

I have two installations - "main" and "drone" - and a single interface directory. The drone's interface directory is symbolically linked (junctioned / symlinked / etc) to the main one.

That means I update / install in one location, and all get it.

When I want to disable mods for my drones, I just hit the Addons button at the character selection screen and toggle off the ones I don't want.

This gives me a single point of maintenance even though I have two installations.