Installed mine and all is good!
Thank you Netman66 and all the others on this thread. I purchased the controller and the trim piece, price was as mentioned $142 / $9.45. Took all of 15 minutes to install (took me longer to dig out my torx bit and a putty knife). Took the truck in to have it reflashed, the service department knew what to do, and I was in and out in 45 minutes. Trailer brake shows up in the EVIC now. Haven't pulled my RV out of storage yet, but I don't foresee any issues.
I ran into similar feedback from the guy at the parts counter when I was ordering the parts (blah blah blah, not suppose to do it) he didn't think it would work, but I told him about the info on this thread and the comments about the 1 vs 2 plugs under the dash (obviously I have 2). I walked him out to the truck and pointed it out, and he wanted me to tell him if it all worked out when I was done. I think they'll be prepared for future people coming in now.
Speaking of the 1 vs 2, haven't figured out any rhyme or reason to why some have it and some don't. My buddy bought a 2010 1500 SLT CC shortly after I bought my 2010 SLT QC (it only had 1), his only has 1 plug. I traded in my QC for my current RAM (which has 2). Only difference is mine has the sport package???
Anyway, thanks everyone for all the info. I would have never tried this had I not seen the thread (since Dodge told me it wasn't possible), and I would have been stuck mounting a Primus brake on the dash like I had in my QC.