Developing a custom flight mode in px4

Hey there!
For the past few days, I have been working on solving a research problem. Subtask of my problem is to add two freewheels on either side of a multicopter and then enable it to traverse on the ground (Something like in this work ). To accomplish this I assume I would need to add a new flight mode to the firmware in which I can provide a constant thrust and use mc_att_control for the attitude control when on the ground. The solution must be such that I can control both attitude and position when on the ground. While flying, the multicopter may operate as an ordinary one.

I also followed these links ( PX4 Research Log 10 and PX4 Research Log 11) but they now seem outdated.

I am not sure if a new flight mode will help, Is there another way anyone would like to suggest.

Thank you!

I used a trike undercarriage, steerable nose wheel, small pusher motor and prop on a scratch built 400 size quad. Separate slider and pot on ttransmitter for ground control. Also gives a different control in the air. Worked ok…