Flux was revolutionized by Chatham and their process uses a seed. Its well known that growing from a seed creates a far better ruby/sapphire as its closer to a natural one and its relatively cheap. Your gonna trash tier jewels if you use no seed. Also, the process you described is the same thing just without a seed. They just used trigger words like molten magma instead of science. They use molten liquids under pressure over time. The seeding method is more common due to being inexpensive and better for jewelery.
What experience are you basing this info off? Do you work in this industry?