Assume you have tried setting up a POI in your missions, then have each wpt use that POI? Then depending on how you have your wpts arranged, you can fly around the POI.
Granted, its not a smooth orbit via mission which is needed, however its a work around.
Another workaround is note your alt, GPS lat, lon, gimbal angle, then using a waypoint to position (then cancel mission), or position by hand, start an orbit mission.
Yeah its a lot of workaround for what should available or a good feature, however its a workaround while waiting.