Hello there! I've been working with your script but I ran into few problems. They're pretty minor, but I just want to throw them at your direction so you know them.
By default, RPPVX process the walking pattern like this: 1,2,3,2,1,2,3 - repeat. It cycles, from 1 to 3, to 1, etc.
But your script changed that so it goes 1,2,3,4, 1,2,3,4, 1,2,3,4. It doesn't cycle backwards. I can probably dive in the script and try to change the pattern settings.
When I start the game with my main character using your extended pattern script. It goes to 3rd pattern, but immediately switches to 1st pattern. It's minor but you can see character change its pattern when you're not doing anything at first - (game start, teleport wrap, etc.) It's kind of big issue for me. They aren't supposed to do that in my opinion so it irks me.
The script doesn't affect any filename that doesn't have $ in front. So that's fine... until I used my custom sprite that only has 3 frames, named $raven, but in the game, it acts like he has extended patterns so it only shows partial raven sprite. I can avoid this issue by setting it to %, though.