@wmschultz You could take a look at my YouTube Channel and blog - links in my signature.
As DC said, I have been using Diamond mixing hot ends for a number of years but more recently have been trying to develop my own 6 input mixing hot end. I've used Mosquito heat breaks (but all metal heat breaks are not good for mixing hot ends which might have loaded but static filament - excellent for any other type of hot end where all loaded filaments keep moving forward).
I currently have 3 hot ends under development - all are water cooled.
One is a single input standard type of Chinese crap. The second is the 6 input mixing hot end with PTFE lined heat breaks. The third is a dual input, all metal hot end designed to always have a mixing ratio of 0.5:0.5 such that both filaments are always moving forward. This latter version is an "E3D volcano killer" but it uses modified Slice Engineering parts. For reasons of intellectual property rights, I can't publish much about it.