Yep happy to give you my scientific process on the fall of lure.
My first cast with the lure I check sonar, cast, count on the splash 1000-1, 1000-2, 1000-3 and so on. When line stops getting pulled across water and settles, that count is to the bottom. So if 10 seconds to bottom in 20fow this equals 2 feet per second.

I also use braid with a 6-8 foot leader of 15# fluoro.

This works when I'm retrieving and working the swing. If drifting, you have to account for full drift speed so you might have to let out more line to keep at or near the bottom.

The size and type of blade may affect it a bit but not in 20 fow. Maybe in 50 fow. But still the process gets you in the neighborhood. Try to keep baits above the fish by a count or two because they love to eat up more than down.

Rickerd