I have previous experience of setting MAXDOP settings for on premise OLTP & OLAP servers when you know the number of cores at your disposal. e.g. if I knew I had 16 at my disposal I'd set my MAXDOP to 2 or 4 for my OLTP system.
I just joined a project and noted the core production database is set to MAXDOP of 1, prohibiting any parallel operations.
It is a dedicated server (so no elastic pool) Premium P11 server so DTUs abstract the exact amount of CPU, memory capability. Without being able to tell how many cores you are dealing with, is there a sensible starting config? finding it a little tricky to port on prem best practices to Azure SQL.
The test servers are a different config with a shared elastic pool, so no easy way to test specific execution plans there either (especially as everything is written through Entity framework ORM)