Rudeofus: Thanks for the info.
Years ago I used to use a 2-step (or maybe it was 3- step ...it's been a long time) for RA-4 print processing and I always used a good rinse between steps and found it gave better results than not doing so. It also prolonged the life of the chemistry because it prevented carryover. However, with color film I have always used my chemistry one-shot. But based on that experience, I assumed that I would give a good rinse between steps.
I generally shoot color only in large format but, on a trip this June, I will be shooting in medium format as well and I appreciate your advice about that. The reason I'll be shooting more MF in color on that trip is simply that Velvia 50 is no longer available in sheet film formats and I don't like Velvia 100 so I plan to shoot color in MF and B&W in my usual 4x5" and 8x10" formats. In fact, when I shot what Velvia 50 sheet film I still had on hand a couple years ago and also Velvia 100 when I ran out of V50, I thought something had gone wrong with my process when so many sheets had a magenta cast. Then, as I sorted them, I realized that all the bad ones were the Velvia 100. Velvia 100 exposures were fine (rated at E.I. 125) but color cast was bad. The Velvia 50 (rated at E.I. 32-40) sheets were beautiful as always. I miss that film in LF but at least it's still available in MF. I'll test other E6 sheet films to find a good sheet film replacement but not before my trip in a couple weeks.
It sounds like the Tetenal kits may be the way to go for me. However, I did contact a European supplier of the full-blown (6-step) Fuji Hunt kits to see how much shipping would be. I haven't heard back from them yet.
I see that some people feel that the 3-step E-6 kits may not produce archival results. Based on my experience, I'm guessing that if there is such a problem, it may be due to insufficient washing of the film but I may be wrong and there may be something else that could cause that problem.