You can do a search on risers and find lots of discussion. Some replace the top triple clamp with a Heli Bar, some use blocks from GenMar and others. I just ordered a set from GenMar for $99. 1" up and 1/2" back.
Most, if not all, manufacturers do not recommend the spacers for the Gen II ('06 and newer) FJRs. IIRC, its because of the adjustment and the design of the Gen II triple clamp, so they recommend replacement.
In other words, any liability issues are on the buyer if there is a sudden catastrophic failure or a fitment problem.
I just installed the Gen Mar risers on my 08. Harder to install than the Gen I risers. Don't really see the half inch movement back toward the rider unless they were counting on the adjustments in the stock triple clamp. They also didn't match the Gen II paint on the handlebars very well. Nice to have the 1" higher though.