Haha definitely having fun, enjoying the lessons a lot.
Sorry if I wasn’t being clear enough, I meant to recreate this view:

Being able to paint metalness in accordance to the bump map.
Whereas in solid shading you can’t see the bump map, only the metalness: 
Can only vaguely see where the metalness is being painted in Material Preview (disconnected the color, only helps a little):
Material Preview but different node setup for texture painting:

Not as good as in the video but much easier to see without having to look at really specific angles. Also using the built in HDRI (Dark Room, I think?)
Is there a better way to recreate this? :
Sorry for the long string of images, appreciate the help!
Here’s the blend file: https://drive.google.com/drive/folders/1r0Za5oIPnavZkhV02dgKIjr6Jwh1dTll