I have read that Dutch and Swiss growers have been successfully cloning from clones up to about 20 times with no noticeable difference. But I have also heard (from multiple sources throughout my life of growing) that every generation cloned from clones you lose precisely 20 percent of potency. Whereas I doubt this, I do believe something is happening. I am somewhat familiar with genetic degeneration. I believe when the the plant cells split and begin to multiply in the regeneration process a bit of the code is not changed, but weakened. Also I am familiar with decreased chemical activity rate, as I have seen the degradation of THC, CBC, CBN, and CBD through certain processes such as heat , absence of heat, compression, light, and so on. So I know that this tiny chemical molecule, when at its most potent, is highly active (spinning fast). Degeneration may lead to a slowed activity rate (less potent). Potency is not relative to just how much resin content there is, but also how psychoactive that organic chemical resin is. However, this does not stop me from taking my own clones from clones. But I usually only do it a few times. I like variety.
Hope this helps