I am part of a team that working on a prototype for a heavy lift drone. I am using the Holybro Pixhawk 4 FC . We are in need of Custom air frame mixers or software for a Quadrotor x for a 14 foot dia prototype that we are building now. We also will need air frames mixers for a 24 foot dia drone that we have on the drawing board. We are looking at both Hexarotor x and Octorotor x mixers for this size.
If interested please contact me and I can provide more details