Hi - I, too, have a very long history of achilles problems and have had the surgery etc etc.
One of the ops I had included resection of the retrocalcaneal bursa and shaving of the Haglunds bump at the back there. It was a nightmare afterwards and just would not settle. I could be wearing a shoe (ouch) and hold my hand six inches away from the back of my heel and still feel the heat of the inflammation. This went on for eighteen months and I was pretty much crippled. Then I had an aprotinin injection! It was miraculous: within hours of having the jab, the inflammation had settled right down. At least it enabled me to work with two feet on the floor again and released me from spending half the night hunting around for a cool place on the sheet to rest my heel.
Yes of course you must examine all the biomechanics involved - but I'm sure you have. And of course you must deal with the trigger points and fascia in the whole leg and hind quarter. But I guess you have. We achilles pro's have done it all!
I have also had autologous blood injections. But that's a story for another day.