This would have been nice from the get-go but might be too late now. Perhaps if Diamond was the max teir and awarded "diamond credit" and then Crystal titles/frames being an achivement awarded at the end of a season for the top 1% on the data center.

They could just give us re-skins of the PvE raid teir gear as trophy crystal rewards alongside every raid patch/pvp series cycle, and new titles every series to commemmorate that specific series such as <Crystal Keeper> for series 1, <Crystal Dominator> for series 2, <Champion of Crystal> for series 3 etc. etc.