Not sure how much of a problem this is for non-synthetic cases; the testcase I'm looking at fires events just once per node... One thing that might help that particular testcase is something like our eval cache that will just return the function for that string without compiling. Is that feasible? Can we gather data on whether it would be worth it?

How much faster is eval comparing to "real" compilation+execution when the code is called only once? We could call the eval few times, and compile only after that.

A bit ugly testcase, but focusing event dispatching in Shark shows where the time is spent.

I'm not convinced this is even a bug. We could memoize here. But, you know, we could memoize just about anything.