Well, I installed 00.13 on my non-hacked, non-soldered, still-in-trial DSA815-TG, and I can say with complete confidence that the firmware version number on the info screen has changed to 00.13.
Since two of the five Rigol products I own have been exchanged or sent back to Rigol for warranty issues, I am a bit reluctant to open up my DSA815 and perform the hardware hack. I am also avoiding leaving the unit on (so as to burn it in and ferret out any hardware issues), as I don't want my trial counter ticking down...just in case I do have to resort to the hardware hack.
I wish someone much smarter than me would find a non-invasive hack for the new DSA815 firmwares. I applaud all of you that are trying!
The 10hz RBW is the only option I would actually pay for, and of course you can't buy that option.