This is because I have one app that wants to start in the middle of the spaned monitors. the problem being the 2nd monitor is to the left of main monitor. The app centers from the left edge of main monitor causing the app window not tho display in viewable area.
This is an excellent idea, and one that I have on my to-do list for a future version. I anticipate that this feature will be included around version 3.4. Thanks!