Hi Mark,
sure they are? We just check for core.create in the frontend and if you changed the acl settings that should work fine
(But it's probably not a good idea to allow registered users to submit events, as long as registration is public..
The frontend organization area is not 100% hardenend for security and spam - so you should trust / know users who are organizers..) For everything else there will be a public (or any ACL level you like) event submission form with Matukio 5.2
Kind regards,
Yves