Jason, I have assumed the achilles is from "too much too soon," but does that ring true in your experience?  My doc is also a runner who is a trainer at EMU (Ypsi) and has read a bit about bfr, but he hasn't tried it yet.  Last I saw him, he was considering it for himself, too, which would be great for me!  He diagnosed the achilles as resulting from overuse and advised RICE, along with exercises and stretches.  Just wondering if that makes sense to you, too, or if you have experienced/heard of anything similar. 

Very often pain in the Achilles Tendon is due to a problem with, or hypertonicity (tightness) of the Soleus muscle.

Check out www.TrekoClinics.com. Scott Hadley who runs the website, and gets a few mentions in Jason's book (which is well worth the read) has a free video on the website where he talks about getting stuck into the Soleus muscle to relieve the pain referring to the Achilles Tendon

I'm on-board Jason. Keen to read, discuss and debate