Hagbanes use the same icon as swift bows, which can make inventory management annoying because both types look the same. Instead of making totally different hagbane weapon models/icons (although that would work too) I think you could just tweak the icons so that hagbanes show a green glowing arrow instead of a regular arrow.
Secondly there is a similar issue with glow skins. Weapons have a little whorl symbol to show which ones have an illusion applied to them. However it doesn’t differentiate glow skins from non glow skins, or glow skins with different colours. This isn’t a big deal but it can lead to some annoying situations, for instance when applying an illusion to an item there is no way to tell the colour of the resulting illusion until after you apply it. This will only get worse in the future as further glow colours will likely be added as DLC at some point.
To solve that problem you could simply add a coloured outline to the weapon, a “sparkle” effect or a border around the icon if a glow skin is applied. A simpler option would be to add a coloured star or dot somewhere on the icon (the top right would work), this would be just like the illusion or favourite item symbols only coloured the same as the glow effect.