Hey James, I think you figured this out already, but answering for the sake of anyone else with a similar question -
Yes, you can connect N devices for N possible ports you have - you just have to specify which one you want to talk to in your trigger (which you always start by specifying which path/device to message to, anyway)
For your related questions - I think this post may provide some insights as well Programmatically Connect to Serial Devices with Player Triggers
Feel free to update with any additional things you have learned 