In cura 2, there are advanced dual extrusion controls. Some of the items added were advanced temperature controls. We a Standby Temperature, Starting Temperature, and Final Temperature.
At the moment, the extruder not in use will sit at standby temperature. As the printing extruder finishes its layer, it will slow ramp down to the "final temperature" Once it reaches final temperature, it will switch to the inactive tool head.
The tool head will not move away from the print towards the priming tower until the previously inactive tool head goes from standby temperature, to initial printing temperature. This can leave defects in the final part as hot end(s) are still hot enough to melt directly below them.
We would like the tool head to move to the priming tower while this heatup and cooldown of the tool heads occurs.
@alexei I do not know how large of a lift this will be. I placed this in future release, but it would be great if we could get it in the 2.6 stable release.