Is it possible to specify a different collation for the data vs the entities within a single database?
Yes.  Turn on partial database containment, and you’ll get a case-insensitive catalog collation along with the collation of your choice for the data.

In a contained database, the catalog collation Latin1_General_100_CI_AS_WS_KS_SC. This collation is the same for all contained databases on all instances of SQL Server and cannot be changed.
The database collation is retained, but is only used as the default collation for user data. By default, the database collation is equal to the model database collation, but can be changed by the user through a CREATE or ALTER DATABASE command as with non-contained databases.

See https://docs.microsoft.com/en-us/sql/relational-databases/databases/contained-database-collations?view=sql-server-ver15
And note that Azure SQL Database always uses contained database collations.