A command instrument setting or incrementing a parameter value, nested in a sub-event, wont execute, if the parameter is set to local. It seems as if the parameter scope was only the nested event and excludes the parent event (which I don’t think is a really desirable behavior!).
EDIT: a conditional triggering inside the nested after the command instrument does work, which confirms my hypothesis about the scope. At the very least, I think the parameter’s value could be propagated to the parent(s) if the “exposed recursively” option is checked…