Sorry, but there is no historical custom for this.
1981 does not a custom begin.
I agree if you are going to do it, do it right, but hardly is this some insane breach or protocol or responsibility.
The guys an idiot, everyone knows he’s an idiot, and of all the dumb things he’s done this is beyond trivial.. but its nice red meat for people who are going to get upset about anything he does instead of the real stupid stuff he is doing in the world that is likely to cost their kids and grandkids.
This is just white noise.
Actually, President Ford tried to juggle his actions on a stairway ramp just like this and ended up falling most of the way down the stair.
Yeah, I guess we should all just shut up about it, then.