I suppose so. That didn't occur to me until it was too late. The 6.61 PRO C2 firmware installed without problems anyway. (I should add that in my searching everyone seemed to be quite oblivious to this TLS matter, so good on you for pointing that out.)
By the way, there's no convenient way to sort the games in the PSP menu, is there? I found many references to something called the "PSP Game Structure Utility", but when I finally found a working download link on some Russian site, it proved to be quite underwhelming; the utility only provides the semi-random unidentifiable names of the folders in the PSP\GAME subdirectory of the PSP's internal storage, meaning I'd have to manually match up each folder name with each game.
Media Go again, I presume. I suppose that would kind of leave Mac users in the dark, unless it runs under Wine or something.