While you may be playing the game on PC, you are using your PSN account’s save data to play the game. As your PSN account is your active account in your cross-save setup, all progress made, gear earned, etc, is being made on that PSN based save. Once cross-save is deactivated, all of that data will only be accessible on that specific PSN account. Your Steam account has no Destiny 2 game data of its own, and it would be a completely fresh start. In your original post, you mention adding a new Xbox account, and a new PSN account. If you remove your current PSN account as the active save, you will be giving up access to everything on that save. That includes characters, weapons, armor, collections, triumphs, and progress. All of the game data you’ve been using, is permanently bound to your current PSN account, and cannot be transferred to another account. If you only want to add an Xbox account to your current cross-save setup, maintaining your current PSN account as the active save; then you do not need to deactivate cross-save. As you do not currently have an Xbox account linked, you can simply add the account to the current activation. Just make sure that you have the correct Xbox account login credentials before proceeding.