Odoo is great, but when it comes to multi-company there is still quite some work, and if you add multi-domain then it gets more complicated to use it out of the box.

Defining the right way to handle the relationship between each component is not easy.

In my case I am wondering how best to approach the use of multi-company.

When we send orders, from one company, the link for review might come with another company domain,

Or we might want to show a product on two websites but not on a third one (if we have various ecommerce on the same account)

Depending on the domain, we might want different invoices layout, messages, footers.

1 user = 1 user email, but then....emails always go out with the same signature and email address.

What is the best way to handle all those situations?