You mentioned using your open toe foot .... are you using your AccuFeed?
If not, you would be best to do so, as that would help with the control.
Then just stitch and turn as necessary .... simplified because you have the knee lift.
The FMQ foot would be perfect ... so long as you feel in control of it, when outlining.
For some, that is more difficult that using a regular foot, and doing the extra work of the turns.
It's a cute panel .. have fun with it!