So I was running for All armor 1.16+ solo speedrun and its really hard because of netherite armor but then I had the idea of using repeating seeds that make ancient debris, diamonds and structures repeat (you probably know them) but is is considered a cheat?

I don't know for sure but on set seed runs, seeds are seeds.

I think it is allowed but I'm not a mod so you should ask them

Thats totally fine. Just make sure you submit to set seed.

its ok but you have to say that it is set seed ! else it will be considered a cheat

I have submitted a run with repeating seed and it got verified

oh ok thanks!