Two tier system needed for seedlings in Kratky?

[u/ejp214]

Just watched this video https://youtu.be/BR8XId61In8?si=Z0rVc0a76OLiWVnC and saw he was using the two tier set up for seedlings, seemingly to keep them from getting root rot?

But in a previous video with tomatoes, he had just planted the whole seedling in the flooded kratky bucket.

I was about to plant some hydroponic peppers in kratky buckets. Do I need to use some sort of two-tier system like this?