how do I set Braven 805 bluetooth as my second rank speaker after headphones?

Since starting to set up my system and learning to use a DAW I have had to learn more about sound control than I ever thought I would. I want to set up when I plug in my headphones, it routes to that, so I have realtek as my default and that works. However, when I unplug them, it reverts to my puny laptop speakers and not my nice ones, which can either be connected via bluetooth or via normal headphone jack. I want Realtek default when headphones are plugged in otherwise another default. With conditionals (if, when) being such a part of code, I hope this is possible.

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