How about a system like the existing cats where you lock the mast step into position and walk it up, but instead of having stays, have a gate at chest level that you can lock around the mast? It would be extremely easy to rig with very little chance of dropping it.
This may be a good moment to familiarize yourself with the F12 design as it stands now.
With the pushrods, you secure the bottom of the mast to the mainbeam by sliding a bolt through the mast section and two eyebolts that are secured to the mainbeam. The mast is laying horizontal and parrallel to the hulls. The other mast sections are now inserted and possible the sleeved sail is slid over the mast. The whole rig can now be walked up and it will fall into the brace that the two pushrod together form. Slide another bolt throught the mast and the eyes and your are done. An alternative here could be a brace that rotates in front of the mast to lock it. I haven't decided here yet.
An alternative way of rigging would be to fit the mast and walk it up without the sail slid on it. Then the boat can be layed on its side and the sail can be slid over the mast that way after which the boat is righted again.
I have to move the rig into the pods on my landyachts and yes it can be done but I found that at my posture of 6 foot 2 and 90 kg that it can still be a muscle job. That is why I spend time on working out the above setup.
Wouter
