Hi, the 100 speed limit is probably the summer time one, right?

OpenStreetMap is not about changing values back-and-forth. Many applications also work offline.

I'd recommend adding the summer speed limit as a separate tag like
maxspeed:conditional=110 @ (Apr 1-Oct 31)
and having the usual maxspeed as
maxspeed=90

I don't know what the dates should be exactly, but they should be taken conservatively. Better to show lower speed limit than a higher one.
