QLC? It's not the one for me
Each time you add another level, you add complexity to the drive circuitry plus you reduce endurance and so you need more and more complex error correction algorithms to safeguard the data. And all for less and less gain in capacity. From 3 levels to 4 only gives you a one third increase, and (heaven forbid) from 4 to 5 will only give you one quarter. Is it really worth it?