I've tried using Arena to accomplish a full dome install. it doesn't work. the edge blending is the problem, Arena cannot handle the compound curves, and multiple overlaps that a 4 projector install in a dome environment requires.
I think that IRmapio has plans of implementing this in the future, as with the latest release there is a default quad radial preset, but still the edge blending can't handle the compound curved surfaces.
I think the biggest issue is VJ software developers access to a proper full dome theater.