Not fully compatible with pistol tubes - Strike Industries AR Enhanced Castle Nut / Extended End Plate

I like the red Extended End Plate. It balances the other red parts I have on this AR pistol. However, I had to use my standard Castle Nut instead of the Extended because I have a Phase 5 buffer tube and the Enhanced Castle Nut would not slide back far enough to thread the buffer tube on the lower receiver. The Phase 5 tube is shaped differently than a standard buffer tube. I was able to install it fine this way but without the look of the SI Castle Nut.