Feature Request: Retract while Combing

[lance-greene 7]

So we have a large format FDM printer that is 30ft long and uses a pellet extruder, and we use cura to slice prints on it. We've had some unique issues pop up because of the size of the prints our machine does, that warrants features that normally wouldn't be needed... like retracting while combing. (or a much further zoom, which we got implemented in 2.6...thanks Ahoeben)

We can have really long travel times on this machine, and normally we have combing turned on as retraction doesn't work very well with the size of our pellet extruder, but that means that after a long travel, the barrel has heated and expanded the pellets inside, which causes oozing and more importantly reduces the pressure in the barrel. so when it finishes its travel and starts printing again there is a slight delay of flow while pressure is built up again.

If you could have the functionality of combing (having the machine do its travel moves inside the part when possible) while also having it retract, that means i could set a very low retract of 2 or 3mm, but have a much higher retraction priming value which would build pressure back up in the barrel, and the combing keeps the part clean.

[lance-greene 7]

This feature could really help us out. We have one of the largest 3D printers in North America, and would like to be able to use cura for our large projects, but some of curas limitations are preventing us from doing that.