Four ideas here.
a) Allows Time Warp to increase the highest secondary stat of each individual player OR
b) you are able to directly modify it. Pick between Crit and Mastery.
a) Allows Alter Time to be cast on another player (versioning) while you keep your own. This would be on a 30 minutes to 1 hour cd to discourage class stacking OR
b) Makes Alter Time Raid wide (5-10 min cd) but gives you a much bigger time frame to trigger it manually or automatically to account for other players and getting the raid topped off - lesser error on behalf of the mage.
Bored @ work and figured I'd throw these out. Would like to know if any of these suggestions would even be taken into consideration, and if those criteria have been met for TW (a,b) and/or AT (a,b), discussions on how to incorporate it for more raid utility without imbalancing PvE and/or PvP.