I have a lot of development experience in this area. I have done SSD/flash firmware with RAM between 16KB and 8GB. The algorithm for each of these approaches gi

I have a lot of development experience in this area. I have done SSD/flash firmware with RAM between 16KB and 8GB. The algorithm for each of these approaches give different perform characteristics. But you can implement hybrid algorithms in between for example 32KB or 256KB adding more performance features. The complexities are the most in these hybrid algorithms. It is certainly feasible to do these in single chip products in USB sticks. I know for example there are some USB drives with SandForce controllers. But the reality is the USB stick market is quite price competitive. They tend to use bargain basement NAND quality. People rarely write the drives to fill capacity before tossing them into their desk drawer. In summary, it is technically feasible but the market base is price sensitive.