My experience has been that with 1x19 5/64” cable, beaver arent going anywhere, swivel or no swivel. I have lassoed something like 500 beavers with them on dry land, and in water/shoreline situations (none under ice ever for me), and while I have had a rare few that worked on the cable enough to have only a few strands left holding, but I dont recall ever actually having one break or chew the cable and get away. Probably 95% or more are alive when I get there. I do know others who have had beaver work and break cable with similar setups and no swivel, but I guess it just hasnt happened to me yet. And if one does, one in over 500 wont bother me too awful much. Maybe 2/3rds of these 500+ beavers were caught with no swivel at all on the snare, after I stopped messing with the swivels years ago.
Now raccoons are another story. I have lost them due to cable being twisted/chewed and broken using 1x19 5/64” both with and without swivels (entangled so swivel stopped working). If I were after raccoons I would definitely use swivels and try to keep the swivel working, but beavers just dont seem to get away. I have always bought cable from Newt, for what its worth.
I have had a lot of discussions about swivels on beaver snares, and people who’s opinion and experience I respect sometimes disagree, and I am not saying they are wrong, but we all use what works for our situation and needs, and for mine swivels appear to be unnecessary on 1x19 5/64” cable.