You can create two custom functions, one for each firefox window with the URL specified, and then attach hotkeys to them and use your Stream deck to run the hotkeys.

You can then create two triggers that look for the Firefox filename and window text of each URL, and move them to a specific size and location. We have guides for creating custom functions and working with triggers below.

Thanks!

Custom Functions: https://www.displayfusion.com/HelpGuide/CustomFunctions/

Triggers: https://www.displayfusion.com/HelpGuide/Triggers/