The front-end user feature seems great, though limited. Can users:
reset their password?
sign-in via email address (in addition to the default username signin)?
How easy/involved/possible would it be to create user-profile pages with unique urls (keyed by username, such as site.com/jimmy or site.com/fred?
Relationships. This is huge. I’d like to be able to associate content with users, but assign and edit it dynamically (via front-end forms and based on user actions - such as incrementing/decrementing counts and such). Possible?
Is it possible to dynamically create content from the front-end (again, via forms)? (PS: Statamic can do this, so it must be possible with Kirby… just not sure if any customizations are needed or not.)
I believe the user part should be possible.
Reset passwords should be possible with $user->update(), guess it would be better to build something like sending a new password via email.
User log in via email should also be possible with $user->login() and authentication. Just match the right fields (create a different landing page and redirect to the panel if necessary).
When a user is created a trigger can be set that creates a page with the username, see here.
User names and attributes can be filtered and generate dynamic content.
There is no solution that is ready to use, though.