The intention of nosqlprotocol is to support version 6 of the wire protocol and that is the version it during handshaking reports both as the minimum and maximum supported wire protocol.

However, it appears that that causes the MongoDB Shell to not always use MSG packets that were introduced in version 6, but earlier packet types as well. In particular, if the convenience functions are used (and not just runCommand()) then older packet types are used.

Reporting 0 as the minimum supported wire protocol version and 6 as the maximum, seems to cause the MongoDB Shell to only use version 6.