SaaS maturity level depending on the number of tenants (nodes)

I am working on a mid-range web application that my client plans to convert to a software as a service (SaaS) model and sell to Customers. I read on SaaS and still understood that there are 4 levels of maturity

A client of mine wants an architecture similar to maturity level 2 (customizable, with a one-to-one relationship between tenants and instances). I also think my current architecture fits well with this idea, although I have a lot of work to do to make it customizable.

My question is about tenant numbers and maturity relationships. Up to how many tenants is this maturity level viable? I don't know yet what my customer base will be, so in my proposal I want to suggest something like:

• Maturity level A for XX-YY (e.g. 0-50) tenants
• Maturity level B for tenants YY-ZZ (50-500)

Is there a popular consensus on the number of tenants ideal for each Maturity Level? If not, how can I analyze my application and make an appropriate decision for my application?

TIA!