I have rehearsed doing this but not yet attempted it. Any hints or suggestions? I would be smiling if I could pull it off. Autopilot or locked helm? What is "heavier air"?
I recommend Andrew Evans's "Thoughts, Tips, Techniques and Tactics for Singlehanded Sailing", a free download available on the Singlehanded Sailing Society website. He and several other have posted YouTube video showing the various techniques for jibing: main first or pole first, end for end or dip pole. Evans advocates the main first jibe.
I jibe the pole first, then the main, with the autopilot. The key is to ease the sheet sufficiently before attempting the jibe, then COMMIT to the maneuver, particularly sticking the pole on the mast, the most difficult part in heavy air, while the boat is rolling and the sails are filling. Be careful making your way back to the cockpit to avoid an accidental jibe.
With the spinnaker, heavy air is anything above 15 knots for me in my non-planing boat. For a boat that planes downwind, like an Olson, you could probably fly a spinnaker solo in much higher wind speeds. Hoisting and dousing are not as challenging as jibing, although you must be well-prepared, step by step, for your intended procedures.
I have YouTube videos of my flying the spinnaker solo, but no jibes yet: