How many categories can discourse support?

Well, it’s for a new small project and I expect it will take ~1 year to reach 1000.
But I would like to have a solution that will allow me to grow and not have to migrate away / redo all of it.

What is the limitation with many categories ?
Is it because the UI asks/ receives for all of them by default?
If that is so, can some form of pagination be implemented to mitigate this?