I've used the overlay feature for "flat" videos many times and I've recently purchased a 360 camera.
It would be great if it was possible to overlay lap timer info onto the 360 video.
(I know this couldn't be done the same way as currently as you are rendering a new video.)
I don't even know if YouTube supports some kind of multi-layered video (e.g. transparent timer video on top of 360 video)?