Add to my concerns:
If you breach the palace at night (and don't have a +AP), you'll get a bounty, Dawn will RAISE that bounty immediately, Dawn infection damage, you might get nuked by Bell Tolls declaration, guards will attack you; then you get a chance at the King.
If your breach the palace in BROAD DAYLIGHT, you'll get a bounty, but it won't raise until next day. The only declaration that would bother you is the one that makes guards stronger IF there was one on the tile you wanted to enter (whereas the night breaker has to fend off 1-3 boosted guard attacks). The guards will only attack if the Night Moves Declaration occurs (and they might prioritize Banes), or maybe you'd get attacked by palace Banes if you are in Overtime mode and that declaration is chosen (not sure if they can move to other palace squares or just out).
This seems a tad unfair to Nocturnal clan members.