Hi dc42,

Cura developer here ^^

Relative extrusion can have rounding problems.
Nevertheless we now have a PR for relative extrusion, and I am willing to merge.

I don't see any use in making the E-values relative by default for RepRap firmware, though. If users have already been printing with Cura then there's no need for relative extrusion any more.
Instead I would like to make the E-values absolute by default, unless a users changes the setting for Relative E-steps by hand.

What do you think?