I know this isn't the answer you are looking for, and it's a little boring. But, if Wisconsin requires a front license plate then I would suggest:
WI 905LDC
Euro Plates only allow 9 characters, including spaces, and the above works great. That way the cops will likely leave you alone. This is what I did.
A few weeks ago I stupidly took a risk with my fuel gauge and lost the bet. As I was waiting for a tow because I needed to re-prime my injectors, a CT state trooper stopped in front of me. He asked me what my plate number was and I pointed to my Deutsch plate on the front, which showed CT ###LLL. That worked for him, and other cops have left me alone too.
I would think that if you put something else on the Euro Plate then you have more of a chance for a future issue. Just my $0.02 In the end, it's really your decision.