I truly hope to be wrong but I think Jakob is in serious trouble here. Watching his vids, anyone who has dealt with chronic achilles problems sees only red flags from him. He is struggling bad.
It's not just one of his achilles, he has said it's both. He's modifying his shoes to cut the heel counters off, meaning both of his achilles are still very aggravated. He is still running in carbon plated shoes every other run and (from my experience) they are going to keep hurting his achilles, but he doesn't know any other way.