Umm, yeah, no mages required to make crystal. Although it would require a magical scholar to tweak the fabricators to a new shape. If you actually need to use mages to make adamantine then it is way less practical than crystal. Also, crystal, like, it is basically permanent. So a crystal city won't really need any maintenance. Crystal cookwear might be a problem with crystal being insulated, except.. Temperature-controlled heat-circuits. You could probably set it up to have a dial that adjusts it of or to a range of precise temperatures. It would be somewhat expensive, at least until the crystal fabrication industry expands, but a much better produce that a perpetually-scalding plate of adamantine.
Also, mind-reading really isn't that good for legal matters. You have the issue of mind-readers being bribed, lying for personal gain, getting stuck in a casual peer-conspiracy(see the medical industry and deliberately killing people as a matter of convenience or catharsis with a general awareness that it goes on and nobody willing to do anything about it because whislteblowers are several orders of magnitude more offensive than murderers.), or just lying for the fun of it. Then you have genuine insanity where someone honestly believe something incorrect, any study into variation in witness testimony will highlight that this is pretty much constant and ubiquitous. Throw in the threat of religious laws and invasion of privacy and I would much prefer Arstotzkan law.
I would say that it is a fair way for crystal to work. Consider that it is grown from magic, and policed by magic. Crystal is perfectly capable of growing around something, we just use magic to have it grow spontaneously and simultaneously in specific places and not in others. Realistically it would have some sort of ideal shape according to its internal structure, and would be more stable in that shape, but it is not restricted to it.
I am not really clear on what is meant by "batch" and "flow" but if we are talking about individual units then... Well. it is magic, it is capable of making a whole object instantly to exact specifications. What better than that?