Good morning,
I wish to highlight what in my view is a bug.
Using the concatenate node in the modern user interface, when a connection in the middle is removed it is not possible to delete the input port.
You can eliminate the input port only if you eliminate the connection at the bottom.
This is an issue as the user is forced the delete the connection to the bottom and reconnect all the other inputs.
I ask to consider this and amend the node accordingly.
Stefano