PX4 for traditional helicopter

Hi. I am new to the open source flight controllers Ardupilot and PX4. I was hoping to get the Pixhawk integrated with a “traditional helicopter” (single rotor collective pitch) and wanted to know whether the state of the current PX4 stack allows for easy integration (i.o.w. plug and play)? (I could not find documentation on setting up a helicopter for px4 stack) Also, it appears that there is more information on forums for Ardupilot and traditional helicopters than px4 - is ardupilot related to the px4 stack in any way or are they complete independent developments (I was wondering whether the attitude control module is ported from Ardupilot and thus have similiar setup/parameters etc.).

Thanks for any information…
Regards,
Yash

PX4 and ArduPilot are very different, although both can run on Pixhawk (as can Paparazzi, probably others too).

The EKF used by the two projects share a common author, but setup and parameters are not transferable.