Arborist safe working practices (2011) guide for Ontario that is available online indicates OHSA 'rules' and stating that the final anchor for a friction saver or rope will be around the main stem and a secondary tie in shall be used with ANY sharp tools. That's as far as it goes.
Truth! I had a boss once in another trade who stepped on a large red tack, he's hoppin'round like a maniac, while he is pulling the tack out I tell him to throw it in the garbage, he chooses to throw it into the shop in a fit of anger....... steps on it again......same foot.....
What? Just set the TIP the first time from the ground and you will only need to screw the link twice, once on set up and once on removing the climb line. ;)
We had snow, not now.
On a serious note, I use a 10mm delta link, a tight alpine butterfly to keep it from falling if I'm blocking down...
I know companies that have a no climb policy, I had a tree guy at my place today stating some municipalities are frowning on dead ash climbing, nothing on fines. If there were, don't think bylaw enforcement would move fast enough.