Consider delayed resize of inactive tabs
When you resize the iTerm window, you get annoying notification for almost all tabs.
At least Terminal.app and Gnome Terminal resize the inactive tabs when you switch to them, rather than immediately. IIRC konsole does this too. Also, Firefox behaves this way, I often see responsive web pages reorganize their contents quickly after I change there. So iTerm seems to be the exception.
To figure out the behavior: I recommend to run zsh or bash <= 4.2, and set up a WINCH trap that runs "date".
In case of Gnome Terminal, at one point it was a deliberate decision that we wanted this behavior, since rewrapping the contents on resize requires linear time to the number of scrollback lines, about 0.2 sec / 1M lines on my computer. I've no clue how it's implemented in iTerm, it may easily be irrelevant here.
Another advantage is that if you switch tab, maximize, restore, switch tab back; then the app running in the first tab doesn't see any resize event at all, since it just doesn't need to.
It's not a bug that iTerm behaves the way it does, but you might want to consider this other approach for some of its small advantages. There are disadvantages too, e.g. when you switch to a fullscreen app (e.g. mc) you might see it quickly resizing rather than already waiting for you at the desired size.