Is it possible to run multiple workers in parallel, calling the same stored procedure in CosmosDB?

I have a bulkDelete stored procedure, almost identical to this one, and a C# console app that calls this procedure, let’s say with 2 workers.

Each worker has its own list of partition keys, so they work on non-overlapping partitions.

However, based on the logs, I notice that 1 worker achieves the same deletion speed as 2 or more workers.

Is this even possible? If yes, how would you implement it?

I need to delete more that 500+ millions items from the DB, so I’m searching for the fastest approach.