For what it's worth, I had a set of spacers made at a machine shop (still have them) for my 16" Lincoln LS wheels. I ran them for years with zero problems.
Aftermarket universal-fit spacers can be dangerous due to the lack of material, so they may have a propensity to crack. The spacers I had made are custom machined out of round stock aluminum to perfectly fit the MN12 bolt pattern and hub with very little play. They are 1/4" thick.
It is possible to safely run spacers and LS wheels.
1996 Mercury Cougar XR7
4.6 - Dynomax-Equipped - Tranny Cooler - 3.27 T/L - 125k Miles