I think its also possible to switch the client DP module in a different mode (by SW).
Then you can transfer data, but debugging and deploying is not possible anymore.
This worked at least with older FW (4.1.x)
Debugging and Deploying was possible via COM1 then. But this was (and is) slow, and I’m not sure if it’s still possible in FW 4.2.x.
I always use Ethernet for data transfer (ENC28 or builtin).
By this you can use USB for debug and have data transfer at the same time.
This also provides a galvanic isolation, when you don’t need to debug and the USB cable is disconnected.
Galvanic isolation is important if you measure analog values and that kind of stuff.
Galvanic isolation for USB is possible (we have it on our custom board) but it needs some more electronic components.