Paperless SaaS

I have a SaaS idea that I am planning to deploy:

Offer a well established open source software named Paperless-ngx (https://github.com/paperless-ngx/paperless-ngx) as a web service, to people who are not technically competent to set up a server and a docker container.

This way, customers will get their own scanned document archiving space, without the need to backup, monitor etc.

Each customer will get their own space, in the form of a subdomain, e.g. https://client1.appname.com.

I will charge a low monthly rate, to cover administrative & server costs. An idea is to offer plans based on storage used.
Each user will get their own docker container, which might get expensive in resources.

The container/subdomain orchestration code is almost ready (using Python).

I am open to suggestions and why not business proposals.