The version checks for filtering the setParameter key-value pairs for starting up mongod and mongos binaries in tests is done in appendSetParameterArgs() in servers.js. The current state of the version checks can be a little hard to parse because we have to check if we are dealing with the latest version of the binary (!programMajorMinorVersion) or a previous binary version ({e.g. {programMajorMinorVersion >= 440}}). It would be nice to find a way to make these checks easier to understand.