After watching the new Any% WR (and, honestly, that was a lot better than my RNG-based strategy), I noticed that the run used medal rooms (unlocked before the run)...
Aren't (already get) medals for NG+ category though?
(I know there are medals that you can obtain before starting the game, but after those, you are still forced to play the game to obtain all them)

That is correct. I actually did not verify those runs myself; I was away for a while at the time the run came in, and the run submitter was awarded moderator status to compensate for my absence. I'll take a look at the run and try to contact dylaneka about the issue.

You can delete my pb if you want I can do some run without using these medal rooms

You can use the medal rooms, but you have to earn enough medals during your run to access them. The game has a button for clearing all your medal data; just hit that before you start your run.

hey, sorry for only just seeing this, and I honestly not sure how to address this, I'm gonna leave it for now but if someone thinks i should change it I can.

and honestly when i set this series up 3 years ago i really didn't have any idea what i was doing, i wanna take this more seriously now though.

I'd be all for getting into speed-running this game, so if any changes to rules do happen, please update them so I can see them. (Such as medal rooms, whether speed up is allowed on steam version.)

I also would like to get into speedrunning this game potentially. I would like to be updated with posts about rules as well.