JDS can work in Coinbase or Full Template mode, depending on config. JDC can ask for Coinbase mode. Those scenarios are not tested.

JDS allow Coinbase mode + JDC ask for Coinbase mode = DeclareMiningJob should not be exchanged + Block propagation should happen only on JDC side
JDS does NOT allow Coinbase mode + JDC ask for Coinbase mode = SetupConnection should fail
JDS _ + JDC does not ask for Coinbase mode = DeclareMiningJob should be exchanged + Block propagation should happen from JDS and JDC

This would require also writing code in JDS and not only the tests as JDS does not take mining modes into consideration at this point(beside the SetupConnection phase)