A nothing issue. Let a wad of roots develop, use your judgment. I'd say maybe 6 roots about 2" long would be enough. Keep in mind that before your plant will give you what you want, it will need to grow roots. Lots and lots and lots and even some more roots after that. You will vomit at the amount of roots you will need to deal with when this is all said and done. Knowing that, let the clone develop enough roots to get a good start in its new home. When the roots really start going, the plant will be at it's happiest so you will need to be the judge of when it's had enough of this good thing. Time for stage 2. Too early and stage 2 will take longer then you expect as the plant will still need to grow lots of roots before it will grow to the size appropriate to the pot. The pot is limiting the root development so it's the pot size that determines final height. Wait too long and the clone will over grow or become tangled in the cloner system. You don't want that either. Couple weeks, few sets of roots, few inches long and away you go. Not a big thang, as long as I'm not doing it, or then I will fuc, em up too.