An interesting patch for an interesting sprite. This patch allows the moving ledge sprite to use two separate, custom GetSpriteClippingA routines, one for its player contact check, another for sprites. The values for each may be changed as needed to make the moving ledge sprite behave precisely as desired (because note that, as demonstrated by the last two .gifs, the sprite is somewhat quirky with or without the patch). My only remark is that throwing sprites upwards through a ledge sprite on a solid surface can still be a wee bit dodgy, but overall this patch makes the moving ledge much more properly responsive.
(Slowdown in the .gifs is the result of recording, not in-game slowdown.)
Tested with Asar 1.71, Lunar Magic 3.03, SA-1 1.31, Snes9x 1.59.2.