LookML architecture/organization (w/ multiple customers)

[David_P1]

What’s been your experience in organizing your lookML, specifically when provisioning reports to different customers. I am in the process of setting this up and would love to hear your thoughts on:

1. Do you favor having a model per customer or only a single model with access filters? pros cons?  
2. How do you handle same metrics, but different definitions + ad-hoc metrics per customer. Do you “extend” views or do you create different dimensions with “required_access_grants”?
3. Do you implement a Hub & spoke model using layers and refinements?
4. Any other suggestions?