Massive weapon trait

the agility penalty is showing on the character, but i’m not seeing any evidence of the extra dice roll happening, is it behind the scenes or do i need to roll it again

I’ve asked about this before, the dice roller does not take this feature into account. You have to do it manually, unfortunately. My table does it by adding a damage dice to the roll, then reducing the result by the lowest value, which seems to be the quickest way to do it (rather than, say, rolling an extra damage die seperately and then trying to recalculate on the fly)