ProSelect works really well when connected to a TV or projector using an AppleTV and AirPlay (connecting your computer wirelessly to your screen) provided you have a good fast WiFi connection from both your computer to the WiFi network and your AppleTV to the WiFi network. if not, you can connect one or both devices to your network using an ethernet cable to get the fastest speed connection.

With OS X Mavericks and now Yosemite, Apple's AirPlay option is getting better and better.  The previous limitation that AirPlay only supported one mirrored monitor is gone. So you can now use the AppleTV screen as a second monitor by selecting Airplay's Extended Desktop mode. In this mode, you can use ProSelect's Mirror Display Area option to show different information on both screens. See the "Using Two Screens" section in the ProSelect Reference Manual for more about this feature. 

While testing this, we found some screen identification and monitor setup swapping issues and when using ProSelect with a AirPlay screen on Mavericks and Yosemite and have made changes to rectify these in both ProSelect 2014r1.10 and 2015r1.2. So make sure that you are using these versions of ProSelect (or newer) if you are using AirPlay.

Note: See this article: ProSelect on Yosemite