It did accept the code but nothing changed. Well, there are more on the list (like GPS), but I'm satisfied with the way it is now. I won't be transmitting (noticeably) and I do have an OCXO here.
My highest frequency signal generator is 2.4 GHz, and personally I haven't worked with anything past 1 GHz so far. I do intend to move on to learning about and attempting to design microstrip filters. The stimulus/response suite combined with my 3 GHz USB VNA and signal generators should let me somewhat comfortably work at around 2 GHz, which is enough for now. The ability to test something at up to 6 GHz is just a bonus.
My only gripe about this SA is the fact that it's quite obviously meant for older technologies. Basic 3G tests and AM/FM modulation. I was originally looking at the SSA3021X Plus but wanted that extra range past what the hack would offer. I'm actually upgrading from a Spectran HF6065, so dropping below 6 GHz felt like a downgrade. After making an offer I got this thing for $1600 with free shipping. At first glance the Siglent looked better, but upon closer inspection the Agilent takes the lead despite being a 2003-2006 vintage machine. Also, the TestEquity label says 20 AUG 12. So there's even a chance that it was recently calibrated!
Thanks for all the help with this! I appreciate it!