So I doubt there has been any idea how 500 jeweler could come about considering most ascended trinkets are Unique and developing a system to create them would probably be too complicated to develop effectively. Instead of making ascended rings, how about giving a big nod to Guild Wars Classic and introduce a craftable Signet of Capture. Signets are essentially rings with seals on them used to authenticate things much like a signature. In the world of Guild wars, they are rings that carry spells for no cost. Being rings, they should be something a Grandmaster Jeweler should be able to create, no? Now for the system.
After getting 500 jeweler and doing whatever related tasks are required to unlock and craft the Signet of Capture, you get an ascended item called Signet of Capture. You then use it to gain a utility skill called Signet of Capture. You can only have one of these available at a time and it does not do anything until you fight and kill certain bosses. The Signet of Capture Utility skill will also be used up and replaced with the acquired skill. The skill received would be dependent on the boss killed and the profession you were on at the time of capture. Also depending on the type of skill received (Healing or Elite), the Signet of Capture could leave a blank spot instead.