C_TransmogCollection Missing Source Help

[AmiYuy]

TorelTwiddler is coding an addon that adds a line to item tooltips to tell you if you have learned a transmog appearance (Can I Mog It? - Trying to get it on here...but it's being difficult for some reason).

So far we've found what we need from existing functions, but can't find the one that will tell us if the item is eligible for "You've collected this appearance, but not from this item". This tooltip is available in the game through CVar missingTransmogSourceInItemTooltips and C_TransmogCollection.GetShowMissingSourceInItemTooltips, but there doesn't seem to be a function in C_TransmogCollection that provides this information. Or if there is, we're missing it or how to use it.

We have tried almost all of the C_TransmogCollection functions and PlayerKnowsSource in particular but it returns seemingly inconsistent information.

PlayerHasTransmog(ItemID) returns whether the player has the transmog from that item only, but doesn't include if it has been learned from a different item, so the result is that the addon thinks the appearance hasn't been learned at all.

We're looking for something like:
PlayerHasTransmogAppearance(itemID) - returns bool of whether the player has the transmog appearance, regardless if this is the exact item it came from

or something like these two example functions (so we can make our own)

GetAppearance(itemID) - returns the visualID of the item
PlayerHasTransmogByAppearance(visualID) - returns bool of whether the the player has the transmog appearance

or instructions for where this data is stored (if it's stored client side).

So does what we're looking for exist and we're missing it? Is there an easier way of getting what we need?