Sorry, I don't have any info about the FJ mount you are asking about, just wanted to post up another option for your set up.
I have the Rugged Ridge XHD rear bumper with tire carrier (I think Smittybuilt is the XRC, maybe you meant XHD? RR might have an XRC, I don't know) and I use the RR Hi Lift jack mount. http://http://www.amazon.com/Rugged-...9288073&sr=8-1
It can be installed low like in the stock pictures on Amazon for a bumper without a tire carrier or it can be installed higher up to clear the tire carrier using the same mount, but a different set of holes. Here is a pic of mine installed with the tire carrier:
I like that it can be locked so your jack stays put. This system has worked well for me. The only real downside is that if you have the hard top, you have to be very concious of what order you close the glass and tailgate in. My wife always tries to close the tailgate first and if she were to do that with the Hi-lift installed, the jack would swing over and break the glass. For me it hasn't been a problem because I am used to closing the glass first since that is the only way to secure it normally.