My proposed way of breaking the logjam with city of Boston has two prongs:

1. Have several independent people simultaneously and persistently asking for a letter allowing them to have a subdomain. Provide social proof that at least a few people want the city to provide this service.

2. Obtain a letter from another MA locality which is more willing/able, to be able to show the city that its possible within state rules. I was planning to give it a go with Cambridge.

I am happy to forward my correspondence with the city to you or anyone interested in giving it a go. You can find my email address if you look.