Not all diamond types/classes are being manufactured. Synthetic diamonds will always be different from natural stones specifically because they lack natural imperfections. Not everyone wants perfection.
Sure. On the other hand, if the synthetic diamonds were the flawed ones, you'd be saying "not everyone will settle for imperfection".
Or, modify the growing process so that it has a greater element of chance to it? (this is likely multi-dimensional)
A diamonds primary value is the history of it's making. People are unfortunately always going to be paying more for a diamond which has been digged out by hard labour than created in a lab.
Keep in mind the value of diamonds is mostly a perceptive one. I am pretty sure if you only did synthetic diamonds it would soon fail to be valuable as the "womans best friend"
Really, diamond is one of those stones where it is the less true. Partially because of brilliant marketing, partially because in such a tiny clear stone the effect is mostly to dull it (speaking of it physical characteristics, not the emotional response).
That is not the case in Rubies or Sapphires. Emerald is meant to have imperfection.
So you went with a "natural" N/I1/fair?