this is completely false, only [censored]ed up 5 seconds one-slot mods have this issues, it's easily fixable manually, check out my old hulk over snake vertex, it has a huge size-mod, and that issue is completly fixed...
of course if you only use the edit all option, it wont work right, because it messes up the Y translation for Y-axis moving animations
ive made/used plenty of size mods using a fitmotionetc and it has the ledge grab issue
besides oneslot size mods are easy to make and more convient for everyone since they dont have to worry about getting rid of another character just to have another
O and my power is back on