How to handle deployments crossing hundreds / thousands / more of "tenants" or "customers", each with API pricing, volumes, discounts, etc. that are potentially unique

[SSYH]

We have many customers, and plan on using API Gateway (currently AWS) to do API forwarding as needed. For a given (functional) OpenAPI spec, we may have that 1:M relationship with SLAs; what is recommended best practice (or vision / backlog / roadmap) approach to managing such deployments? This would include per-tenant (per-customer) SLAs preferably integrated with monitoring / alerting / reporting tools which can then present in operations-facing and CSM-facing dashboards.