Hello,
This is a general suggestion for now, if it gets support by many people I'll get into the details, help you decide on the details, work on it full-time, or just step out and let you handle it.
The concept is simple: Have one way to do something, and ONLY one way.
For example, the <nav> tag? Just use a div with a role, or a UL with a role, maybe set some standard roles to be used in the role attribute.
That's just an example, but you get the idea.
God bless