MavLink mission command from QGC mission not supported on ArduPilot

ArduCopter Copter 4.5
1

I’ve created a “Structure Scan” mission on QGC.

When I try to upload it to my copter running ArduPilot, I get an error:

qgc mission transfer failed
qgc mission transfer failed1920×1080 142 KB

Just for grins, I uploaded this mission to a copter running PX4. Then I connected to that copter using Mission Planner:

structure scan on mission planner
structure scan on mission planner1920×1080 264 KB

It displays the mission OK. But when I try to save it back to a copter running ArduPilot - it fails.

structure scan on mission planner - error detail
structure scan on mission planner - error detail1920×1080 266 KB

I know there are differences in the MavLink commands supported for missions between PX4 and ArduPilot. But I would at least hope that ArduPilot could do everything that PX4 can do.

Is there any chance this particular difference might be addressed?

Thanks!