I know there was a massive thread on this but I can't seem to find it (the search feature brings back zero results for "bug" or "the bug").

If you have a piloted and fully active Bug, can you choose to use Invulnerable on the main dial to reduce the damage and then use one of the bonus dials to take the remainder of the damage?

Yes, the Bug can use any damage reducers on the main dial because the rules for the additional dials are that the player can choose to assign damage taken to them. Damage taken is the term used to refer to the damage value after reductions are applied.

Thanks. That's what I figured but lately I've been surprised as to how things have been ruled so I wanted to make sure I wasn't missing something.