Coc seems to believe that grafting significantly changes the rate of growth. I recall him saying that potency goes way down and that one would be well served to graft, then groe, then root for a while in order to improve the alkaloid profile.
Very interesting canndo - I will also experiment in "shading" the cacti throughout their growth phase. I've heard that our cacti friends seem to respond to this "stress" by significantly increasing alkaloids within. Coc mentioned pereskiopsis spathulata is great to graft L.W. onto. I'm glad I have lots of time to decide what I want to do. I have little space available, so that is also a factor. Thanks for the replies everyone !! Will update periodically-