Postprocessor for fan control?

[Rick Zehr]

I've noticed that Kisslicer does a miserable job of fan control: when it reaches the set height, the fan immediately turns on at its full speed setting, which fouls up the PID tracking and immediately cools the extruder by 10-12C, then rebounds and overshoots, then undershoots again, etc., until it finally settles down at the set temperature again a while later. This is on an Ultimaker 2 with extruder cooling fans.

Cura, by contrast, ramps the fans up slowly from zero to the target speed, which maintains much more stable extrusion temps.

Is there any piece of SW (preferably for Mac) that allows for post-processing to create gradual fan onset without having to manually insert M106 commands to increase fan speeds for each layer? I'm aware of the Tweak at Z plugin, but it's not available in Kisslicer. Or is it?