a)Crossfader and b)Push and "prepend _parameter_shortname"

Hi all, first time poster here ;)

I made a device (based on the stock multimap device), where you can map various parameters in live to a single knob. Now the only parameter, which is not mapable is the crossfader. Is this a bug or am I missing something?

Furthermore I use "prepend _parameter_shortname" to change the displayed name of the knob. While this is reflected in live's gui, push doesn't show the new names. Probably this is a fault of the python script for push or do I have to add some code to my device?

Thanks!