Commerci Bosses and drop rates?

It's like a reactor, but it's not; it definitely is an invisible, invincible monster. You wouldn't be able to target it with skills if it was a reactor. What I mean is, say you were a Luminous in a map with a monster and a box, Reflection wouldn't bounce off the monster and hit the box, like it does with the invisible, invincible monsters on the ship.

Potentially, I would say it's possible that it's not affected by drop rate because it doesn't die "naturally", but rather because it's killed, perhaps "de-spawned", through some kind of script, I guess, upon the boss dying.

Commerci might actually have a de-spawn command at the end of every individual round. I don't know what happens if the timer runs out and you have one of those monster life mobs on the bottom of the ship though. If it is killed if time runs out then that confirms it.