well, that’s the whole point of dynamic capacity : you can’t compute the load 🙂 That’s the reason why operators do not care about this feature. They’d rather monitor the load precisely, because it should not congest that often anyway, using default parameters.
But to monitor dynamic AGCH/PCH, you can now monitor the number of Immediate Assignment (resp. Pagings) which are rejected due to congestion. Those are new indicators in B10.