My thought here is don't bother re-inventing the wheel. Other than the intellectual exercise of trying to suspend a Thin Fin, there are already lures out there that achieve what you're looking for.
For instance: There are any number of suspending jerk baits out there that are relatively easy to weight and suspend using suspendots and/or suspend strips.
Another thing, they make these lures called flukes or senkos and it is a relatively simple matter to drift these through pole timber.
If you have true pole timber with very few horizontal branches you might consider a flutter spoon, of which there are dozens of companies. Strike King is the first one that comes to mind, although I know there are others, like the Dixie Jet.
This reminds me of a similar idea I had earlier this fall. I was in a fishing tackle store and I saw a Terminator Twin Spin. I thought that this was a cool looking lure and how hot it could be, in a controlled drop in timber.
So I bought some - 45 bucks worth. I'm out on the lake, rigged up with a MH jig rod and 20 lb fluorocarbon (cause I don't want to lose my lures) Practice cast close to the boat, it looks cool dropping nearly straight down. Throw to a target, drop, drop drop, stops. Oh darn, it is stuck - good - go get it - it is really stuck. Too deep to reach with my extendable pole and multiple tries with the hound dog lure retriever don't succeed. I decide to wrap the line around the boat cleat and back it off with the trolling motor - pop goes the line.
This spot is scrambled, can't fish here, so I move 30 years or so down the tree line and re-rig. 1st cast - stuck again - retrieve procedure repeated with similar results. Re-rig again - move 30 yards, cast again - same result. A $45 lesson, proving beyond the shadow of a doubt that twin spins aren't an ideal timber lure.
A good rock and/or weed line lure, not so hot around brush and timber. I'm not trying to denigrate your efforts or ideas at all, just offering a cautionary tale that cost me around 45 bucks and an hour of fishing time. I'll make more money and buy more fishing toys, but I'll never get that time back.