[pwmtr]

You are not wrong. There are benefits for sharing certificate authority per customer. We actually considered using one authority per organization. However in our case, there is no organization entity in our data model. There is projects, which is similar but not exactly same. So we were not entirely sure where should we put the boundary and decided to go with more isolated approach.

It is likely that we would add a organization-like entity in the future to our data model and at that time sharing certificate authority would make more sense.