Just wondering: What are Brexit supporters happy about today, i.e. what are some positive changes from their perspective?

Not clear how that's going to work in practice. Pretty much every product involved in the prod chain for goods sold into the EU will have to follow its regs. Could end up being for most products anyway. Yet, the UK will no longer have a say. Also likely to apply to services too.

Sure, but a product and its subcomponents made in the UK will have to follow EU regulations to be sold into the EU. If it relaxes constraints, then it won't be compliant. The rules of origin will also increase complexity.