I would consider just cutting the mast wiring. And that's what some/a lot of boatyards do. Then while the mast is down re-wire the mast with improvements such as a conduit in the mast if it doesn't already exist, and re-imagining the method of of passing the wires through the deck, and creating a terminal block for disconnecting wires for future mast drops.
Avoid the thru deck fittings outside the mast. They eventually leak and sooner than later get stepped on creating connection problems.
My fav is a pvc tube epoxied thru the deck inside the footprint of the mast that sticks up an inch or so proud of the deck. The wires can run thru the deck in the tube without connections until they can be made inside the boat in some accessible location. In future mast droppings the wires can be disconnected without the drama of trying to disconnecting from the dicey thru deck connecters, getting your fingers inside the mast footprint (With the aforementioned consequences).
Cutting antenna wires needs more consideration/expertise than I can offer. Instrument wires can go to terminal blocks but be careful that cutting such might void a warranty.
Definitely use messenger lines.
As for mechanics of the lift: Of course remove the sails, boom, and its hardware including disconnecting the mainsheet, vang, and reefing lines where appropriate. Disconnect all the lower shrouds and bungie to the mast marking the turnbuckle lengths.
Remove Running rigging such as halyards that run to the cockpit and tie to the mast, and including lines for vangs, cunningham, topping lift, spin pole up a downs if they exist. Anything that goes with the mast and disconnects from the boat.
At the time of going to the crane there should be only the forestay, backstay, port and starboard cap shrouds connecting the mast to the boat. And they should be loosened to the point that the pins can be removed.
Leave little for the yard workers to decide or that impedes their progress. I'm speaking from my experience and disappointment. Their solutions to roadblocks won't be the same as yours.