Alpha Mask data not saved for added outfit slots

[AliceChurchfield]

If you add an additional outfit slot to a character via the Settings > "Add additional clothing slot" button, the "Alpha Mask" selector doesn't do anything in any of the garment categories (i.e. "Top", "Bottom", "Underwear", etc.). Changing its value has no effect, and indeed the change doesn't even seem to be recorded properly. For example, say you switch to outfit number 8, and you select the "Bottom" clothing category. Using the Alpha Mask selector, you choose, say, "Gloves". Then, switch to outfit number 1. You'll note that that selector updates to reflect whatever the Alpha Mask setting is for the Bottom category in outfit 1. But now if you switch back to outfit 8, it will still show whatever you had in outfit 1. In general, it always seems to show the last value it had, which it can only seem to get when you open outfits 1 through 7.

I will note that I have had some ArgumentOutOfRangeException and IndexOutOfRangeException messages in my BepInEx console when I switch to additional outfit slots. I don't know whether this is related to the problem I'm reporting here.