How do you handle Groups / SharePoint / Teams creation

We have limited the ability to create Groups to the members of a Security Group in the O365 Admin portal (a process described already here and I think also in Tony Redmond's excellent and must-have book). We have also limited the ability to create SharePoint sites in the SharePoint Admin portal. This means that the option to 'Create Site' from the SharePoint portal is not there for end users, and they also don't get the option from Outlook.

The bit that I'm less certain about right now is how the DL to Group process is going to work, but I assume that I will be able to convert the DL to a Group, that it won't be automatic. We expect that our SharePoint model will change once we have more Group-based SharePoint sites replacing previous DLs plus a separate SharePoint site.