Not sure if this is an original idea or not, but here goes.
Had an idea for the rarest Bind on Pickup profession recipes, formulas, patterns, schematics, etc.
Instead of binding to the individual crafter who loots it, they could bind it to the guild.
Then give the GM a new interface that allows you to designate two or three players of each profession as the Official Guild XYZ, where XYZ is Enchanter, Leatherworker, Engineer, Jewelcrafter, Blacksmith, Alchemist.
That sort of scheme might lead to additional guild loyalty by individual players.
It also might encourage guilds who run into trouble to actually try to put in the hard work to repair their internal issues, as well as their reputation in the community, rather than disband and form a new guild.
If the crafters faced losing access to those highest level patterns, people might think more about overall guild success and teamwork.