the title is straight forward im asking if you can post another speedrun (mainly faster) on the same category

Are you really asking - "if you submit a run, and then get a faster run, can you submit the new run too?" Of course...

Also, the slower time will automatically be marked as obsolete, so there’s no need to edit or delete it.

right, okay (sorry for the late response ive been busy and im asking that question, i had to make sure i could alright)