So I thought the vortex generator suggestion was a good one. So I made some wedge-shaped vortex generators from small rubber door stops:
The tried them at different positions and orientations on the pillar:
and then the door frame:
Using these vortex generators I could certainly change the flow, and at times improve it (best results with vortex generators on the door frame).
But I couldn't get anywhere near the flow improvement I got with the aerofoil air curtain. So I might try going back to the PVC-pipe based plastic deflector and see if I can do better than I did with that last time.