Making changes to components added to the Blueprints viewport can not be undone. I made translation changes to the camera, character and added a box and I wasn't able to use undo on those changes.
The components would also be stuck to their new positions, unable to move until the BP was complied, and reopened.
Alterations made with the Details panel could be undone.
Editor undoes previous camera changes.
Camera remains in it's altered state.
There's no existing public thread on this issue, so head over toAnswerHub just mention UE-35480 in the post.