Oh. Just reading your recommendation now. Thanks for that idea.
I was able to figure it out with Vitaly's help from the telegram English group.
I just had to copy that script to a blank USB stick and edit the bluetooth type to 7.
Then while the head unit was running I just plugged the USB stick into one of the USB ports and it auto runs the script. Just like "using the traditional flashing method." as he said in the first post. Now it makes sense.
You're not reinstalling the OS from scratch like I thought he meant. Just plugging it in like the original method.
Once it rebooted my bluetooth stuff all worked. I have my DUDU SWC working now. Thank you!