After looking at one of the lights I'll probably get it appears the challenge will be to hold the nuts on while installing both screws. I'm assuming it can be overcome possibly with plate nuts or nutserts? So it will be a challenge but doable to install the light after paint? Assuming the wiring gets routed before of course. Don't really want to install plate nuts and screws for fairing.
I decided I might need to service the light at some point so I attached with plate nuts and screws. I would really hate to have to get in there after paint if riveted.