I haven't tried so I can't confirm. I highly doubt the mechanics were changed.
When I started speedrunning this it was common to load the weapon immediately and shoot the slasher. Look at earlier runs, you'll see me doing that. I'm sure when you get used to it over time, it gets easier to stop and evade the slashing.
When it slashes you have to step back to be outside of its hit range, then pass along. I guess you figured that out already.
It always hits directly at you, so stay left for it to go and hit left, for example, that leaves room to pass by to the right. I guess it's a quick DOWN RIGHT UP combo to back off and turn around.
The rules say: "Outfit mods are allowed for Haydee only, and any outfit mods that affect Haydee's size or hitbox in any way are banned."
Google translate: 衣装改造はハイディーにのみ許可されており、ヘイディーのサイズやヒットボックスに何らかの影響を与える衣装改造は禁止されています。
Level Leaderboard: The idea here is to offer short runs, attractive to a broader audience. Since there are no 'levels' but individual items to collect I guess one way is go from Start to Orange keycard, from Start to Blue, Teal, and so on.
Just getting the pistol seems a bit short for a category (~16 seconds).
100% is another common category - if anyone is interested we can discuss what to include (kill all, collect all guns, ...)