I am the ARTART reviewer for this document.  Thanks for writing it, it's generally clear.

If I was to give any nit, it is that the "Introduction" seems quite long including detailing a 6 step process - something I would have expected to see under its own heading.

I expect that if I had an existing implementation of ASN.1 and certificate generation, it would be trivial to add this property.  Likewise if I needed to use it, I would know what values to fill in and what my CA was expecting.