For bridge shooting there is a drum extension that allows the spar to go horizontal over the deck. There is a picture of it in Dave Barkers essay. Without a safety wire the mast can be lowered just like you would do with a normal Genoa. That is to use the halyard to lower the mast. Since there is no stay to undo there is no deed to crawl the foredeck, which is a safety factor as well IMHO. I never use a safety wire inshore to allow mast lowering without having to undo the drum at the bow. Offshore there are no bridges to shoot. Sailing without a safety wire does require you to inspect the Genoa Halyard more often and perhaps replace more often to avoid unexpected breakage.
If you don’t use a spinnaker but do have a Spinny sheave in your mast you could use the Spiny halyard as a safety wire. It allows you to undo the safety from the confines of the cockpit.
Over here most bridges are high enough for a Wayfarer to sail under, or they open. I hate bridge shooting for a small mistake can have severe consequences like breaking the tabernacle. Also the rig may block the helm. If I have to shoot a bridge I prefer to moore or run up a beach and carefully lay the mast in a strut, bind the rig together making sure the engine, helm and cockpit are free. Then I safely motor under the bridge only to re-assemble the boat safely ashore or moored again on the other side of the bridge. Most of the time we have to incorporate the other traffic in our decisions, often they are large commercial barges. So, to me bridge shooting is something I only do If a bridge isn’t operated anymore (evenings). I can do it while sailing if I have to, but I try to avoid it as much as possible. But if you are shooting bridges with no other traffic than an occasional day sailor, it is a different matter.