Welcome to our Community.
You are correct in that the Self Employed and the Small to Medium Business version, QuickBooks Online, do differ in terms of functionality.
That being said, there is a Feedback option within Self Employed and this can be accessed by clicking on the Help option in the top right of the screen. This will bring you to the Knowledge Base and give you the option to submit feedback by clicking on the We Love Feedback button.
You can also add your address to your invoice by clicking on the 'Edit work info' function on the bottom toolbar within the New Invoice screen. You will also be able to add your contact number and a logo to your invoice from this options menu.
Let me know if you have any further queries