I would like to see an option added which will move the extruder (or dual extruders) away from a printed part whenever this is a tool change. By default, it seems that S3D will perform a tool change wherever printing last stopped. This provides an opportunity for extruders to drool down onto the part, decreasing printed part quality.
For a small machine, this is not such a big deal... for a really large machine, the distance can be several feet (taking a lot of extra time over the span of a really big print)
I know this can be changed in the Tool Change Script option, but it's not dynamic and forces users to remember to manually change a setting. Providing an automatic option makes it much simpler for the users.