They do use the sub-off-screen subroutine, but those already have an offscreen check for all directions. Do note that in horizontal levels,sprites don't get deleted when going too far above or below the screen. In vertical levels, left and right are no longer delete zones, when using those routines. They do get deleted when they go too far below the level (except some sprites, most notably the sprites dropped from item boxes).
Nintendo manually added its own "offscreen" code that permanently delets them without setting the respawn flag when re-entering the screen. This is seperate from the routines that does that. Due to them being 8-bit distance difference between the sprite's Y position and the top of the screen, it forms a "delete area" both top and bottom.
EDIT: please redownload the patch, I've notice that smw's suboffscreen does not erase sprites above horizontal levels.
Give thanks to RPG hacker for working on Asar.
Nintendo manually added its own "offscreen" code that permanently delets them without setting the respawn flag when re-entering the screen. This is seperate from the routines that does that. Due to them being 8-bit distance difference between the sprite's Y position and the top of the screen, it forms a "delete area" both top and bottom.
EDIT: please redownload the patch, I've notice that smw's suboffscreen does not erase sprites above horizontal levels.
Give thanks to RPG hacker for working on Asar.