I've been working on fixing movement permissions as I go; found another in the Seanport Gym in fact and purposely left a huge one there (through the wall from the back of the Gym) for the time being on my copy because there is a blockup caused by saving within the Seanport Gym (I know, I tested that very bug after hearing about it but used a save state for that test so I could reverse). Ash has expressed an interest in fixing that Gym, and also plans to block it with an NPC so it can't be accessed until it's time to go there. I wonder if he should install a backtracking path on the sides if possible, but I did recommend making switch pushes permanent even if the player leaves and re-enters before defeating the Leader in case someone saves inside. In any case, I'm up on 410 now and also fixed a lot of wrong tiles in National Park, but given the number I have to trek back and retest the area. I'm just about to head onto 410 (already written a walkthrough for all of the game up to Guardian Tower to date), so I could test that fix today.
I think our opinion on what constitutes an error differs. Anything that gives a sloppy look to the finish is, in my mind, an error that needs fixing. Major of course means game-breaking, such as skipping scripts, but in my view any and all errors should be corrected. I commented to Ash about the footsteps during the Imatari Islands events as well; apparently, he thinks it's a nice Easter Egg. LMAO