PowerApps, SharePoint List, PowerAutomate- Public submission. Move item where user cannot edit any further.

The Scenario:
We are using PowerApps as a UI for organization wide users to submit Grant applications. Forms is not an option because users need to come back in and be able to edit. So I created a multi-screen form app that saves the users progress section by section.

What I feel the issue is: With Sharepoint List and PowerApp, "Everyone but external users" need edit permissions but after "final" submission, I needed to take the edit permission away.
What I did.
Two Sharepoint lists, One "Public" and one "Private". The apps is connected to the "Public" list.
At the end of my App form is a question that asks if they are ready for a "Final Submit" The User can answer Yes or No.

I created a flow that when an item is created or modified, get the item, and if that item's "Final Submission" value is eqaul to yes, then it creates a new Item in the "Private" list and then deletes the Item from the "Public" list.

Worked Like a charm. :D