DISCLAIMER: I don't know if the LB2 boss thing was a glitch or not, I'm awaiting clarification.

My silence at the end of this run says it all. This game is cursed... Still, it could have been worse for my second full run through.

MOD EDIT: I'm pretty sure that flying over the boss trigger in such a way to cause it to not spawn properly is a glitch. Same behaviour occurs after level-wrapping. I'm calling this a glitch and verifying this as a Glitched run.

BEN EDIT: Taking the executive decision that the LB2 thing is a bug in the original S3 with tails (like needing to die in Ice Cap), It doesn't violate the pillars of S3(K) glitchless of solidity, and skipping end of act bosses, so allowing for glitchless.