Well, when i got my tlg module I made it work on my mega 256 using the physical serial port 1. I have notice that for some reason, it does not work very well with the serial software library. But using the physical serial port, it work as a charm. I got it to turn relay on anf off no problem.
Now, i've integrated those module to my home, and since they are stand alone, basicaly they don't need Arduino to work, i got one to control a mp3 module controled by a serial port on my sound system.
So to awnser your question, no it does not need the breakout shield presented in this post. I can relate, im not a shield fan ither.