Each table has settings to allow you to configure exactly which records appear in Stacker and exactly which fields. You can also pick which field should be the display name of the record, and if there should be a created by field which sets a default value.
The simple navigation can be edited with drag and drop and a homepage specified.
Your users are stored right in your data source in a user table, and they can automatically register and login. You can use sharing links or send welcome emails to make onboarding your users even easier. It's also just a click to preview the portal as any of your users so you can make sure its absolutely perfect.
You can use permission rules to configure access to data with fine grained controls down to the individual field. Then taking this one step further with Advanced Permissions you can have multiple different user roles in the same portal.
Brand your portal with your color, logo and icon.
And you don't have to stop there, you can create multiple portals inside a single Stacker account.