Trying to get a handle on how snap on weights affect dive curves. I ahve the precision trolling app but cant find snap ons, maybe im missing it in there?

Read in the past that if run 20ft from bait 1 Oz will add 1/3 the curve, 2 Oz 2/3, and 3 Oz doubles it. Is this accurate?

Recent reports say things like 1 Oz 30/30 or 4 Oz 40/40. Is it correct that 30/30 would mean run 30 ft out, snap on weight and run additional 30 (60 total on line counter )?

If so, how do you determine where that puts your bait?

Example, If I'm running ddhj 12s, their max depth is 19 ft, I'm marking fish at say 30 ft so I wanna put my ddhj at 26ft down how do I determine where to put the weight and how much weight to get that desired depth?

Apprecite any help, thanks!