Question on Stock Size/Height

[Lokoliki]

I'm getting ready to do some grafts onto Harrisia jusbertii, and I just had some questions about this (and similar viney stocks) that I'd like to clear up before doing so.
Noticed that the size of the stock can be drastically different depending on who is grafting, but does the size/length of Harrisia (or Selenicereus) have any effect on how quickly the scion grows? And is it worth waiting a few weeks for taller stocks (like over 15-20cm)? I know that growth rates of scions on Pereskiopsis are increased the taller/leafier it is, but does it make as much of a difference how large a leafless stock is? Thanks for the help.

[CactusFanDan]

It should still make a difference, as the bigger the stock, the larger the photosynthetic area, thus the more energy the plant can produce and therefore faster growth.