1. First of all - no need to create a new profile.
2. Open folder which containt User Data Directory. It should be located here - "C:\Users\**local user**\AppData\Local\Google\Chrome\"
3. Copy "User Data" folder and paste it in the same directory or in any directory you want, rename it if you want (example - C:\chrome data\profile1)
4. You need to create as much user data folders as you need sources in Polywall
5. Press Win+R and open each profile by this comand - "C:\Program Files (x86)\Google\Chrome\Application\chrome.exe" --user-data-dir="*Path to profile*"
6. Setup each profile like you need (for example addons, credentials, etc.). Open Chrome settings and set "Open a specific page or set page" as you see on the screenshot below. And add a new page (Put the url that you want to open in this source).
7. Close it in windows mode (If you will close window in full screen mode, the system will open it in full screen mode next time).
7. Open Polywall Designer and create application source with path you opened in step 5. For example "C:\Program Files (x86)\Google\Chrome\Application\chrome.exe" --user-data-dir="C:\chrome data\Profile1"