I'm going to run some power consumption tests at 19V and 24V. If power supply on the board is a switching DC-DC converter rather than linear (which I would hope is the case) then current consumption should actually go down at 24V rather than up.
The vendor I bought the board from also reports that they have customers supplying 24V through the external connector without issue.
Power ratings are usually over temperature and since our application is at or near room temperature this probably also gives some additional head room.
Jacob