I saw this earlier but completely forgot to reply to it.
The OOB Parallax was referring to is actually different to the NG+ OOB. It involves using an enemy's attack to clip you through a wall.
I've only been able to produce it about 2 or 3 times ever, it's extremely random and may be based on framerate too. As you may have noticed physics, hitboxes etc. change a bit at lower framerates. I capped my game to 20fps to achieve this and I don't recall if I ever managed to reproduce it at higher framerates. In theory though, you could technically get OOB anywhere in the game that there is an enemy with an attack that knocks you over like this.
Most of the areas in the game for the NG+ method have been tested already and for the most part they're all useless. The main problem with the OOB using the costume cutscene is that it sends you backwards almost every time. If you use it on the transition between Silent Hill and the Amusement Park it sends you back to the Hilltop area.
I don't actually recall if I've tested the horses part, but something is telling me I tried it and for some reason it just doesn't work in that area. Logic would dictate that it would also take you back to Hilltop like the other transition in the Amusement Park, but I'll do some testing again.
At this point it looks more likely that someone would have to find a modification of the glitch or a new glitch altogether rather than a new area to use it in.
In SH2 you can clip catacomb monster through wall with shotgun hit. Happened 2 times in my runs.
Also monster is killed with 1 shotgun shell more often if James is pushed against the wall.
Since game engines are the same in SH2/SH3, these two examples might have something in common.
Edit: I found memory address that cycles animation on the monster, capped CPU cycles via BES to 95% to see value of flying animation when you hit him with shotgun. Then I uncapped CPU cycles, locked memory address on flying animation value and pushed monster into the wall like this, he stuck but he went throught a little bit. Maybe clipping has something to do with animations rather than FPS.
We have added a new category that restricts the usage of manipulating the game window to go out of bounds via a monster (and also restricts the usage of monster OoBs in general for fairness lest someone get a lucky lagspike). Accordingly, since this category still allows Quick Save/Load the previous