Hi David,
Are you advocating scripting of 2 tick count vis into the error chain and then doing the subtraction to determine the measurement? Interesting idea, but then I guess I need to know a way to tack in those vi's into the error chain. And, often times, there may be some unbundling of an input cluster, in which case putting in the sequence structure ensures that you completely measure the timing of the vi.
I'm not sure I would want to do this with a LV2 global because, to have it be useful, it would need to be reentrant (otherwise you might use it in a vi running in parallel and foul up your measurements).
Thanks, Denise