This is something that I always felt wrong.
I don’t want to add strokes to objects that have none, and especially I don’t want to create boxes around texts.
I could copy properties and paste them around, but how cumbersome is that? I can’t do that to a selection anyway.
Even if my selection only features texts, the problem stands. I do want to edit a selection with multiple leaders and change the stroke to all of them, without affecting start and endpoints and without adding the dreaded boxes to the texts.