The mini-Jenny (5309) worked like a charm, and I got all 297 parts of the download on the first try without a hitch. I think the FAQ here could be a little clearer that this won't affect existing or scheduled recordings, but a search of some older threads here settled my mind on that subject.
So UltimateTV should either retire their misleading page, qualify it with an expiration date, or point the user to the 5309 code, which accomplishes what they were describing on that page.
Thanks for the help! I guess I can continue to live in denial for a few more years.