Here are some resources that I found interesting, and you may too.
The Ultimate Runner’s Guide to Achilles Tendon Injuries: The Scientific Signs, Symptoms, and Research Backed Treatment Options for Achilles Tendonitis and Insertional Achilles Tendinopathy
This article is one of the few that gives concrete, specific information on insertional tendonitis. I had come up with my own approach, after discussing with numerous docs, physical therapists, and web sources. This article, which I found afterwards, pretty much nails it.
Injury Series: Flat eccentric heel drops for insertional Achilles tendonitis
This article, aside from the research paper that the protocol is based on, the most useful resource for those of us with insertional achilles tendonitis.
Insertional achilles tendinopathy management: a systematic review.
Link to PubMed meta-analysis of 118 articles specific to insertional achilles tendonitis. You’ll need a subscription to access the actual article.