Advice on a small pixhawk for small VTOL

Been hanging out on the Dual-motor tailsitters thread, and am starting a new VTOL project based on the Wing-wing airframe. Not much space for a regular Pixhawk. I’d like to go to one of the smaller versions, but I;d like to make sure the VTOL code will run happily on my smaller pixhawk variant, and I’d appreciate some advice from someone with more experience with pixhawk variants as to what to use.