Currently the sync and async drivers are completely separate to each other - they use different types, different packages, even different ways of creating clients (sync uses MongoClientOptions and individual parameters, async uses ConnectionString and MongoClientSettings).

This makes it really hard to use sync & async APIs together - if you want to do some operations sync and some async, for example.

It should be much easier to move between sync & async APIs, given the same client, database, or collection objects (MongoDatabase.asSync()/MongoDatabase.asAsync())

If not, at least consolidate how you create sync and async MongoClient objects so you can use the same representation of a connection & client options.