I loved the moby-dickless mod for ark survival evolved so I made my own that does the same thing. This should work for all rafts including modded rafts but this is untested right now. The mod works by reducing the Leeds aggro range to an incredibly low number in the negatives. The Leeds aggro applies only to targeting rafts. They should still have a normal engagement range should you attack one. This applies to both normal and alphas. Please comment if you have any issues!
IMPORTANT:
This does NOT retroactively affect already spawned creatures. This mod REDIRECTS the wild versions spawners with that of this creature. Already existing Leeds (including alphas) need to be wiped. Not doing this crucial step could result in an exceptionally bad time at sea.