5 hole probe/ Multiple Pitot for Pixhawks

I have a I2C splitter from original 3dr pixhawk. Theoretically, it should be possible to add multiple pressure sensor using I2C to operate a 5 hole probe. Or one can possibly mount multiple airspeed sensor (for research/data collection purposes).

Have anyone have experience with this? Is it possible? Or does it require substantial coding?

I think you will need extra coding to make those additional pressure sensors working

Yeah sure you need to develop a low level driver that could exploit your hardware and create a topic on uORB and publish the value your are getting from the sensor on this topic.
you can look or take exemple of already made drivers in /src/drivers