Thanks that was helpful and exactly what I was looking for.

Now I have the next issue:

If I would like to draw in mm (with shaku showing already as the alternate dimension between[]) but then also be able to annotate dimensions in Inches. What would be the best workflow to do so?

Can I open a copy of the file, change the units I am working in annotate dimensions in inches and keep the previous dimensions in metric [and shaku] still showing?