I may be missing something here .
On my setup screen (I am a simple person) , I have one row per universe or sometimes more than one row per Universe (see examples in the manual)
ie have not tried to group then as has been done here - (not saying this is wrong) , but I took the firts line of the setup and to me it works out as 680 pixels (ie 2040/3) but the alpha screen shows 600 . And the next is = 340 (3060-2041+1)/3 , but alphas screen says 300.