I am just trying to find a way to handle the jib lines while keeping a hand on the helm.
The boat is quite easy to single if you stand /sit in front of the binnacle.
The amount of time you release the wheel is negligible as to not dramatically affect your course. The wheel will not spin back like a car so just release, adjust sheets and return to steerage.
If you are tacking, when you go hard a-lee, as the bow comes through the eye pop the former lee sheet and haul the soon to be lee sheet and cleat. When done well you will be available for steering before you are on the new tack.
FWIW, I mostly single hand and always heave to when lowering sails. I have my halyards run aft and when I want to lower sails the first thing I do is heave to, then release the jib halyard clutch with the halyard in my hand so I can hold it. I jump onto the coach roof while keeping the halyard in my hand and walk forward. Once I am about to the jib I let the halyard go, sit down on my arse and pull the job down. I have a bungie strung between the aft-most stanchions of the bow pulpit close to the deck and I gather the jib in and stuff it under this bungie which holds the sail to the deck, just as it is when I first go out in prep for raising the jib from the cockpit. Once this is done I go back to the aft part of the coach roof and lower the main and use those ball bungies to secure it to the boom. All done. All this being said, I would like to rig a jib downhaul so as to avoid completely having to leave the cockpit. I always raise the main first and lower the jib first, i.e., reverse order. I don't use an autopilot or lash the tiller at all when raising/lowering sails. When raising I rely on the outboard, 15hp, to keep me into the wind, though I should tighten it up a bit as it will vibrate one way or the other and cause me to go off course.
There is nothing more rewarding than being able to single hand a relatively large sailboat and do it smoothly and safely.
I find taking the main down in heavy winds is fairley easy using the 3 reef quick reafing system with all lines running back to the cockpit end of the boom and all lines within reach with one hand on the wheel. Of course roller reefing on the jib is ecential for single handing from the cockpit on any crusing boat. I am concidering getting a spiniker sleeve for our genaker spinniker and I am working on a bow sprit pole made of carbon fiber or heavy wall aluminium pipe.