Prop Question

[smokeonthewater]

ALSO the jack plate will add absolutely NO more force or stress to the transom.... The force comes from the prop and the mathematical lever arm is exactly from the prop to the top mounting holes in the transom and the fulcrum is the lowest contact point of the transom

You could have a 20" motor or a 120" motor w a 100" jack plate and the leverage would be the same

Now a 25" motor on a 25" transom on the other hand WOULD apply more leverage to the transom than your setup. ..
You are worried about a nonexistent issue.... Forget the reenforcement plate..... Instead just look at blocking water... MUCH less strength needed for that.... Plastic would be my choice