A very simple remix. I just removed the fiddly little bars in the middle of the original design, as my MPMD wasn't having any of it without supports, and my Slic3r profile was lacing the supports into the areas within the model, making them impossible to remove (and yes, I tried changing the settings, with no success). This allows the model to print well, with supports, and without errors.
EDIT 12 April 2019:
I've now successfully printed this on two different Delta printers, takes about an hour at 0.2mm layer height with supports (on build plate only) enabled.