Edging is the best form of active recovery one can do for PE.
I think the comparison between annealing and R-phase is a bit of a reach, as our heating gets nowhere near the required temperatures, and our dicks do not have a crystalline molecular structure. But I also think that metallurgy concepts are very useful for informing successful I-phase work. Breaking down collagen to initiate PE growth is a lot like straining metal.
For P- and R-phase, the IPR model is the best thing to study. Wikipedia is a great starting point. The limiting factors of tissue proliferation and remodeling are circulation (aided by heat, cardiovascular health, and frequent erections), nutrition (protein is the most important factor), and rest (not exceeding elastic stress during remodeling).
Before 5.5" x 4.1" ///////// Now 7.4" x 4.9"