The 20 sec timeout https://github.com/mongodb/mongo/blob/r4.1.3/src/mongo/client/remote_command_targeter_rs.cpp#L84 is not enough for the continuous stepdown config suite.
Need to be
a) increased to 30 seconds
b) look for other places in the code setting the network related timeouts
b) changed to a constant so its easier to find and modify.