Thanks Dave. That looks like a leak, yes. Probably caused because I have been struggling with this part a lot. I.e., I have been struggling with unnecessary/complicated abstractions here, while all I need is to pick up the tripcount later from State.TripCount, because that's where this thing lives. While ActiveLaneMask is a binary op, I think a single argument is best, and that would be clearer than trying to force it to look like a binary op with some sort of dummy 2nd argument which I did here in the wrong way that will be replaced later, I don't see how that really helps.