Behavior when adding more than 1000 events to a notification group?

I have just noticed that the documentation for SimConnect_AddClientEventToNotificationGroup states:

The maximum number of events that can be added to a notification group is 1000

In my app, I add all key events to one notification group, approximately 1800, for logging purposes. I do not seem to receive any errors when I do this (although I am not checking the return status), and I seem to get notification through for all events.
Will this cause any issues? What is the expected behavior when more than 1000 events are added to a notification group?

Also, the simconnect priority SIMCONNECT_GROUP_PRIORITY_HIGHEST_MASKABLE is documented as deprecated with the comment No longer used in Microsoft Flight Simulator… Does this mean that all priorities are maskable?