Hi Mel -
Sounds like a good conservative approach. One thing - not sure if it will help - is to work on body looseners. In particular, ankle rolls. If you have the Chi Running book, they are very well described there. Even better - the Chi Running app has videos of them. In any case, the ankle rolls help loosen up the ankle area, which is helpful for alleviating dorsiflexion. My thought here is if you are holding tension in the ankle throughout the gait cycle, that could be aggravating the issue. So, with that, and working on not pushing off, hopefully you will get some relief on the achilles an lower leg in general. And make sure your stride length is kept in check - shorten it a tad than what you’re used to and see if that helps.
One more thought - did he mention heel lifts in your shoe? There is an ladies’ ultrarunner joke (old) that says ‘You know you’re an ultra runner when you wear high heels to alleviate achille’s tendonitis.’ While I wouldn’t recommend a high heel, sometimes a minor lift of 1/8” to 1/4” can help ease the tendonitis - even in minimalist shoes.
Keep us posted!
Certified Chi Running and Chi Walking Master Instructor