Develop, Color Develop, Blix - Ergo, 3 bath. At least that has been reported here over and over, and I tell them to use a stabilizer or final rinse as recommended by the film companies.
Do you know for sure? I am only quoting a multitude of others seeking advice here and I am only referring to the 3 bath statement by the companies that make 3 bath E6 kits.
Remember that these companies produce no film and do no extensive R&D. Kodak, Fuji, Agfa and Ilford are the R&D companies that do everything. I must say though that Fuji does little process R&D.