I am doing my Quarryman credo and I just had to eat spitroasted batmeat to complete my level.
The next quest was to gain 2 strength and to mine 6 Schist I think.
However, as soon as I completed the bat meat quest, the +2 strength gain for the next level was already completed without me eating anything.
I checked if eating the bat meat made me gain any strength, but it did not (no stats for that matter).
It is nice that the game automatically completes quests for me, but I doubt it is intentional.