Opting for two-buckets has some advantages. The primary benefit lies in the convenience it offers. With a single bucket, you need to to empty the waste promptly once the bucket is full to keep the system going. However, having a second bucket allows you the flexibility to bury the waste at a more convenient time.
Another benefit is the waste has more time to ferment, this is especially good for households that produce a lot of waste. More fermentation time means the waste breaks down faster in the soil. Plus, as the waste ferments for longer, more bokashi juice is produced.
If you are gardening daily, adding the bokashi waste to a worm farm or another composting system, or generate minimal waste you may not need the convenience of a two-bucket system.
Even in the scenario where you empty the waste on the same day the bucket reaches capacity, it will still breakdown successfully. While the waste at the upper layer of the bucket would not have fermented for long, if at all, it still benefits from the microbes present in the Bokashi mix, which accelerate the breakdown.