KMST 1.2.411 - Phantom

If you can steal Continual Aiming, it's a permanent debuff on a monster, so it shouldn't be removed when you switch to Rapid Fire with Combo Attack. They have their own +30% damage and 30% Defense Ignore, and 220% Final Attack activated based on their own critical hit rate. They're definitely not bad DPS.

Not sure if you can steal it but I doubt it'll work permanently on a single boss like you said.

Switching skills is just like dispelling the skill off you, and bosses dispel do cancel Bullseye effect currently.
I have to dismount and Bullseye constantly on dispelling bosses.

Edit: You guys call it Advanced Homing if I'm not mistaken.