Just a follow up for the record,... it was always my intent to load the sketch "and then" do this modification. But as it turned out I needed to go back and make a change to the sketch,.. so i had an opportunity to find out if uploading still works after implementing this hack.
It does not.
I got an error message from the computer itself saying it does not recognize this USB device (in this case, the Arduino UNO).
I then un-soldered both wires that I had installed.. at the USB port, and then everything was completely functional for loading again. Loaded the modified sketch, soldered the wires back,... voila,.. I'm back in hack mode.. works fine.