Furthermore, there is a problem with the inherent usefulness of humours in general.
In Haven the increase of attributes is always desirable as they serve a clear purpose for the development of a character regardless of which role he wants to fill. There's never a point where you have "enough" constitution or agility, for instance. That makes FEP events something you keep yourself invested in throughout the entirety of the game, early to late.
In Salem humours stop serving any real purpose after a certain level. There really exist no incentives to keep grinding for humours beyond the 100s since pretty much anything can be accomplished at those numbers. The only reason to keep grinding is for pvp. It's basically the equivalent of FEP events only raising health, stamina, intelligence and strength in Haven. If that were the case you'd quickly lose interest.
So really it's a lackluster gluttony system that has rather pointless gains after the mid-game. Thus there exists the need not just to update how gluttony works but also how humours work in general. If something like Yellow Bile had more uses than just combat people might feel more compelled to care about it. As it is, unless you want to pvp, why bother?
That's how I see it, anyway.