A Zilzul should mean something inherently antithetical to the notion of being Shoves. A ShabbosApp might Taka do that; I can’t see how an elevator does.
First, I’m glad we are maskim that this is worse than an elevator. This is indeed a stirah to being shoves. I like how you put that.
I think the reason an elevator might be considered zilzul is is because you are actively (for lack of a better word) using it, i.e. it is transporting you, whereas lights are just on, albeit benefitting you. I think 29 might be alluding to this point. Agav, my rav may be mattir to visit my grandmother on the 40th floor. With no alternative to walk, and a tzorech gadol, it might be okay. In the situation I was involved in, although there was a tzorech gadol, there was a reasonable alternative to walk.
Ivory, popa is referring to the fact that tzedukim held you can’t even have a fire lit from before Shabbos. However, we’ve always been allowed to have fire/light in our homes on Shabbos, the only thing that changed is that the source is now electrical.
Actively using an electrical device is entirely different.