Anyway, I think such a tool would be highly useful. Also, "progress" is an often overlooked feature, but users actually appreciate it a lot, and often even require it. And you simply can't easily add progress-computation to a system as an after-thought. You have to "weave" it through the design as you build it.
There's also the fact that in such distributed systems, the entity that consumes the result of the computation is generally not the same entity that consumes the metrics.