The 1.5 release has been publihed; now you can disable or enable extruder voices on the fly by using:

$.fn.disableExtruderVoice();

or

$.fn.enableExtruderVoice();

Actually jquery.mb.extruder doesn't have any method to disable a voice line dinamically; the disabled line is drawn by the initialization method if it has the "disabled" param setted.

In the next release (1.5.0) this method'll be implemented as some other issue (for example you'll be able to choose if the mb.extruders should have a fixed or an absolute position...).