Yes I changed lots of things to get it working nicely, I unfortunately didn't notice the missing emojis until after I had finished configuration. No plugins.
Here is a summary of changes I have made:
Disable banner with bnconfig --disable_banner
Set hostname with bnconfig --machine_hostname
Changed default admin email address here (this got cleared after implementing SSO).
Configured email in /opt/bitnami/apps/discourse/htdocs/config/discourse.conf
Removed secondary notification_email from site_setting database table as per here
Set up HTTPS with bncert-tool
Enabled force HTTPS
Set up SSO
And of course GUI wizard, a couple of tweaks inside the interface.
It's taken me long time to get to this point, and lots of looking around the filesystem. But not much changing config really. I think the only file I've edited is discourse.conf, and made a few minor changes in the database.