My Getaway has the Hobie 16 spinnaker kit. So far there has never been a condition or point of sail that I have wished I had a screecher. What sailing conditions do you want the sail for? A screecher on a furler will hurt allready poor windward performance on the boat. It might be slightly faster in light air off the wind. In anything over 10 the boat sails with the wind about 120-135 apparent with the spinnaker. To deep for a Code 0 or Screecher.
I understand wanting to keep the front tramp clear. I'd consider have a bigger jib made and relocating blocks for the jib sheets aft before I'd put a screecher on the boat.