It's great that we can control outer most shell speed, but I like to have infill at a very fast speed, but inner shells at a slower speed. A separate "Inset" speed control would help to control some tight radii.
Yes, this is a big complaint I have about Simplify3D. It's especially a problem if you're using more that two shells, because each interior shell prints progressively faster, inevitably leading to under extrusion for the innermost shell(s) even if the other settings are dialed in perfectly. If there is one feature I consider a MUST, this is it.
I'm really shocked that only one other person on this forum considers this important, which leads me to wonder if it will ever be implemented.