My suggestion is very simple; remove the ability to receive tempering solutions on this server.
4.x started the trend of very high gear ceilings and it drives new players away. No one wants to get 2-shotted over and over again by a max gear, max tempered, +10 plume person while trying to farm BM gear. You cannot fight back and it overall just takes away from the experience.
The grind of getting best-in-slot gear, +15, and full blue manastones is more than enough in terms of character progression for this game. Tempering just hurts the casual players.
I have played this game since version 1.5 and I know for a fact that the most active PvP this game has ever seen was when the gear ceiling was much lower (version 2.5 to 3.0) -- as soon as the gear ceiling was raised significantly (blue manastones, plumes, tempering accs), was when PvP became less about skill and more about gear, and many people quit.