Btw, there is a thread here that shows some of the caudex forming plants, it will help to see how gritty looking the media looks like, so you will have an idea what it really means to make it very well draining:
Good luck, hope your plant recovers in time. The good side it is Spring going into summer, their active growth time.
The thread "Bizarre Caudiciforms" in
Cactus and Succulents forum
