original scselcharacter is 3.79mb
how much does it reduce?
and does it include removing all characters battle portraits, as in "normal characters"?
Battle portraits should remain unaffected, this is just for the stock icons in MiscData[90].
The archive had a limit with how many unique icons could exist in the file and because of that I wasn't able to have a stock icon loaded for every costume (The game would crash if it was unable to find a stock icon).
What I managed to do was edit the module in common3.pac that controls how stock icons load, and change it so that it only loads "InfStc" instead of "InfStc.XXX" depending on the costume and character loaded.
So basically you don't need to have a ton of stock icons to make additional costumes and fighters compatible with 1p modes, and you can remove all of the original ones too since they're only really used on that menu. I think they're maybe on the stage select menu as well, though there might be a second set of those in sc_selmap, I've never had any crashes or problems there before so I never checked.
I deleted the miscdata[90] from the original sc_selcharacter.pac and it freed up about 100kb, so it should probably be somewhere close to that much extra space you'll get if you haven't modified your stock icons. If you've put in a bunch of new ones you might save more, or less if you're like me and replaced them with placeholders (I saved about 40 - 50 kb I think). I think the main attraction here is that costumes without stock icons no longer crash on certain menus.
Anyway, here's the modified common3.pac:
https://www.mediafire.com/?0mfg5475t12q2pcIt should work with the newest version of BrawlEx, just make sure you have a single stock icon named "InfStc" in your MiscData[90] archive, in your sc_selcharacter.pac file. You can have more icons in there but it won't read them, so there's no point.