KISSlicer allows you to specify STL of your built area.Quote
AndyCart
There must be a way to alter Pronterface, Repetier, Cura, etc to take these weird delta build platform planforms into account to maximise build area safely?
If you use deltaDiagonalRod = 2*deltaRadius then it is just a cylinder with the top like this (pictures are for deltaDiagonalRod=250mm):
[attachment 23130 deltaTopLimitSide.png]
[attachment 23131 deltaTopLimitAbove.png]