Duty Roulette: Low Level. Needs fixing.

[Insidious]

Bonus XP is half of the level you enter the dungeon as, and has nothing to do with the level of the dungeon you enter.

Gonna have to say you are wrong on this. The lower the level the dungeon, the higher the roulette reward will be for your first completion that day. Thereafter, lower level dungeons will reward much lower XP per mob and you're better off queueing for dungeons your level.