I use 2 snap swivels
1 at the end of the braided line.
1 that connects to the lure.
the barrel swivel at the end of the mono leader goes on the snap swivel first then the weight
that way I can leave the leader and lure on all day.
as far as how much line to make 5 oz go 60 feet deep that would depend on speed
my guess is 1-1.3 MPH
I make sure I have 175-250 feet of line out
the conflict is how to be near the bottom without snagging the bottom
I was told my entire life that walleye in lake Erie are suspended I have not found that to be true in 2019 or 2020
though I troll at 2.5 -2.8 MPH
4 of the biggest walleye and trout I caught have been on the bottom when trolling at .9 MPH
I purposely slow down for 1-3 minutes to try something different and let lures go to bottom
at 72 FOW I was catching a keeper every 10-12 minutes with 5 oz weight thus no need to go to 6-7 oz of weight
in a perfect world I would be 2 feet off the bottom without ever snagging the bottom