I realise you're near feature release now etc but I thought I'd throw this one into the mix, it's something that used to be in Ultramon and would be great if it could be integrated into DF (expecially if it's a quick win).
This is definitely coming in a future version, don't worry. It's something that constantly annoys me while testing different monitor configurations. I'm aiming to have this feature included in either the 3.1.1 release, or 3.2 at the latest. Thanks!