In the scope of https://jira.mongodb.org/browse/SPEC-1469 (and https://jira.mongodb.org/browse/CSHARP-2796 ), it was added clarification of how extraOptions settings can be configured:

(which may be either in the form
"--idleShutdownTimeoutSecs=60" or as two consecutive arguments
["--idleShutdownTimeoutSecs", 60]

which allows specifying the same mongocryptd argument as 2 separate lines in the extraOptions. This requirement was missed. And the current implementation will fail due to assumption that each extraOption is placed in his own extraOptions item. We should consider whether we can change it now since it might be a BC