I'm not going to doubt you as you definitely have more experience than me, and you are likely correct because of said experience. However, I am going to ask for you to elaborate on your thought about why the fact that eliminating axle wrap essentially eliminates my original complaint isn't the source, but the clutch is. I am a mechanical engineer by trade, so please excuse my questions. I genuinely would like to understand the thought process.
Sitting in idle, the clutch is very quiet. Shifting into any other gear is perfect and quiet. Reverse is perfect and quiet. Its only when taking off in first gear that I am seeing the majority of the action happening at my rear diff. The clutch only has 800 miles on it by the way. Its not gotten any worse/better. When I put that 3" worth of wood above the snubber, ALL shudder disappeared.