In that case, you'd understand the difficulties of providing a product or piece of software out of the box with valid certificates without user setup, as you've done (without running all user data through offsite servers).
I too have a working reverse proxy setup or few. I certainly don't expect something using a "localhost site" to come with valid certificates. Unless they somehow get a valid cert for https://localhost
Edit: apologies for the assumption, I didn't realise that you weren't the guy I originally replied to. I'm new around here.
What to say - maybe before assuming that someone "don't really know how any of this works" you may, just a second, think that the person your comment is directed to has written a security reverse proxy and presented on that on one of the largest security conferences.
Or not, maybe that I really do not know how terminating traffic on MY reverse proxy and sending it upstream to MY ubnt controller works. Who knows.