0.5x XP Rate and stopping XP gain for DK starting zone

I wanted to start a DK smurf that runs dungeons at level 55 (to help friends and generally when I'm bored with endgame stuff) but completing the DK tutorial at 0.5x forces you to at least be level 56 and 25%. So I'm just wondering 1. is there a way to stop gaining xp as a dk in the starting zone, and 2. does the minimum xp rate have to be 0.5x? I don't know how many people even utilize it but I'm guessing if they like leveling at 0.5x, would they mind if it was instead at 0.25x? I would assume they might like it more if it was a bit lower.

Make a level 55 DK, then faction swap. U will be ported to your capital city without experience gain.