Languages as subfolder URL patterns in primary domain

[NearlyNormal]

Hi. 

Among the many suboptimal design decisions in Shopify world (chiefly, multiple languages of products cannot be in the same place and need idiotic "apps" to work...what a basic miss)  is one about primary domains and languages. 

We do NOT want the ourbrand.myshopify.com url. 
We have a "primary domain" which is shop.ourbrand.com

And for our languages, we need to use this primary domain.  Otherwise what's the point. 

- shop.bunzaburo.com            (main language, Japanese)
- shop.bunzaburo.com/en/    (second language, English)

This seems impossible, because to be able to have a language's' subfolder, we have to pick the second option in the `Markets --> Domains and Languages` screen. Which forces the *.myshopify.com URL for our store. 

This is so stupid. What am I missing? How can we keep our set domain (primary domain) and have languages as subfolders?