Can i use a custom resource pack when speedrunning?

https://vanillatweaks.net/picker/resource-packs/

i used this website to make it

My PB was a 26:30 when somehow I got really lucky and got 20:35. I know that most people will think I'm over reacting, but I'm really worried people will find my drop in time suspicious. Do I have to stream in order for people to believe me?

P.S. the run was submitted very recently and hasn't been verified. (or rejected)