When doing a speed run, does the fps counter have to be only the fps counter of the game or is it accepted in programs such as afterburner?

It has been said that we can enable accessibility features in any Unrestricted category. Among these, there are options such as decreasing the perception of the enemies, decreasing the aim in the conflicts and even making ourselves invisible. These seem to be against the rules, I wanted to ask a question.

In which categories can I use the game's own timer? Which timer should I use in other categories?

Is there an easy category in the remake? If not, what are the categories?