Yes. This contraption is definitely one of those that is incredibly useful, especially during the wetter parts of the season, or you play a nicer place but the super hits the flood button to keep the owner happy that it looks green.
The last club where I was a member was always soft, which was frustrating. Even medium trajectory tee shots would sometimes plug or bound forward all of a yard, so there was little rollout. I take fairly large divots, so you can imagine how much dirt/mud would cling to the club face. I was always washing golf towels!
I like how you added the magnets... I'm surprised that someone hasn't come out with a portable version of this yet. I'd definitely look at getting one, provided it isn't overly cumbersome.