I am happy to say that raft in Version 4.0 was completely redesigned for easier separation and faster printing. The raft is now only placed where it is absolutely needed, so this would solve the issue that you noted in the post above. You can read more about the new raft changes towards the bottom of the page below:
https://www.simplify3d.com/software/rel ... ion-4-0-0/
We have been getting great results with the raft design, so we hope you enjoy the new changes!