You don't have to go back to the general tab - you can open the instrument's plugin, go to Info -> Outputs and open the effect's editor there. Another option may be to use the plugin list of that module in the tree view. And yet another option that avoids switching between tabs is of course to open a second (temporary) window for the General Tab if you really need to go there, do the changes there and close it again - the pattern tab will stay as-is. I don't think a dropdown that is otherwise completely unrelated to the functionality of the pattern tab is necessary with the presence of multiple alternatives.

It would also be helpful if we could change the "Editor" button in the General page (and the "Plugin" button in the Pattern page) to something more uniform and logical, like "GUI."

I don't think that a button labelled "GUI" or "Editor" in the pattern tab would be helpful, because it doesn't tell you which GUI / editor it is referring to. One could easily think it would open the editor for that instrument, not for the plugin. The button is labelled "Plugin" there because it bring you to the plugin for that instrument. "Plugin Editor" may be more acceptable but there isn't really enough space for that given the current non-resizable UI elements.

Didnt know (or forgot) about the plugins folder in the tree view. Thatll do.

Close at your discretion.