The technique I followed was FMS->WPT, then PPOS to mark the point. I then, still in HDG, turned to the right to the reciprocal heading. I then went to the FMS->FPL page, added the user user waypoint to the flight plan, and then selected hold at the waypoint. I was pleasantly surprised that the inbound course of the hold appeared to be the heading I was on when I pressed the PPOS key; exactly what I wanted!

I think this is worth at least a “Cool Feature” mention in the IFD documentation. While you’re at it, you might also want to mention that the IFD recomputes the course length in the depicted hold each time you cross the hold point. This makes sense, but it was interesting to watch it in action (typically there isn’t a lot of interesting things going on during a hold, so we were messing with airspeed).