Looking at the code I don't see where the flow-editor would be storing up messages or status text. Does your heap display only show live objects or may it also show dead ones ready to be GC'd?
In any case, to get this fixed the first step would be to put together a repro. If your evaluation of the cause is correct, then a simple flow with an inject node and another node set-up such that the status of the second node is changed every 100ms should reproduce the problem relatively quickly, right?