ical not accesslevel public

This new feature is an additional option more, and I like it because users can see the events on the calendar without being able to access the content. They can't register for events if they don’t currently have access.
And as a user, they can see which events are blocked (without access).

For example:

- in a school:
You can schedule meetings such as the School Council, Teachers' Board, and Teacher Training Sessions (or even the Principal's agenda) so that parents and staff can know when meetings are taking place, but they cannot see the details of the meetings.

- in a academy (extracurricular activities):
Another case could be publishing events for students' extracurricular activities at the school, where other parents can see what the school is doing and promote the fact that they organize a wide variety of events, especially for prospective parents (now that open house days are starting). However, since they don’t have a user account, they cannot register because they are not yet parents.

- in an association:
This same approach can be useful for any type of association. Public users can see the events they host (for example, dances, course, presentations, ...), but only association members can view the content and register for the events.

- in a companies ... multiple uses.

@nicor Could you test 'beta2' of this new feature? Thanks.

Sorry, I can only access here on Sundays.
with 4.3.2 (JEM-Project-level-access-to-show-events) I can't download the registered events in ics yet.

The events have public and registered. The global settings have “registered and public” selected under show locked events. 
The menu entry type is “simple list”, access level is registered.

Unfortunately, I cannot provide a screenshot.

Thanks for your test, I have found a small bug in the filter access. 
Change the \components\com_jem\model\eventslist.php line 381:

For this other:

Tell me, if it works.

I have upload a commit to fix it:  github.com/jemproject/JEM-Project/commit/28df7ab29aa1b2e828329f9894337cf601ea75c0

I have removed the two ' and uploaded the file again. Without success. Only the public appointment is exported.