macOS: Running action on multiple drafts – bug or feature?

When I select multiple drafts in the draft panel on the left and then click a simple text replacement action in the action panel on the right, I would expect this action to change every draft immediately. However, it only changes one draft, so a click on the action is necessary for every selected draft. Is this intended behaviour?

That is by design. The actions in the action list (and action bar) are performed on the draft loaded in the editor.

If you wish to run an action on multiple selected drafts on the Mac, use the Run Action... command in the contextual menu of the draft list.