The edge blend in the stage setup works well (I think the actors are a legacy system- it has been talked about that there is a whole new version of the stage setup on the way), it needs a few more helpers (like at least a line at the blend boundaries for aligning, but otherwise it is there and works well, and together (again a few interface details) with the stage key stoning it allows for pretty much any scenario.
I feel like this stuff should stay as is for functionality and the mapper is more for feeding content to stages. How would an edge blend on a mapper work, on all quads that go over a boundary or on selected quads per boundary?).
I would love that the stage setup is aware of its own key stoning and blending instead, that izzy could then deduce the biggest rectangle it can fit across blended stages (lets say 3 physical projectors) and then amalgamate these into a new single stage (it knows how much overlap there is), then once the stage setup is done no more chopping and adjusting for overlap, just send everyhing to the new stage. This is a feature of serveral other well known systems.