Can you leave the camera battery in and boost it with something like this? https://www.amazon.com/gp/product/B07GKMHK6Q/
Not sure I totally understand your wall of text. How are you powering the Hollyland?
If you're battery powering the Hollyland, just get one of these, it has an extra USB output: https://www.amazon.com/gp/product/B07GKMHK6Q/
Edit: changed link