I feel your fear, heck I get nervous just doing those straightforward updates on my Sony BR player with all the disk fun. Yeah it's not that big of deal to change manually, and given that, I doubt many of these CECB mfgers spent any money on a fix post-design (i.e. I'm thinking they were designed before the DST change). From my EE experience, the ugly thing about software mods is that 'ideally' they need to retest&certify everything that is controlled by the software to make sure something else didn't get bugged up (it happens, quite frequently too).
Glad to hear these boxes are still working well, I would expect no less for this brand. I mean they actually built in a real power supply!
Still good with my boxes (I don't have any of these) but they don't get nearly as much use anymore. One Channel Master almost daily to tune an HDD/DVD recorder, another one a few times a week to tune a DVD recorder or a second TV (coon-ass picture&picture). A couple of lonely VCR's being tuned by a couple of lonely Zinwells (one Zinwell I'll sometimes hook to the DVDR for timer recording when I'm not around); but hey that Sony VCR makes a fine clock! (although I did have to record 3 shows about a month ago). Two more lonely Zinwells tuning lonely kitchen and office TV's. And the loneliest of them all - an Artec 'setup' in an insulated fabric cooler bag (Dale Jr.!) to tune a 5" LCD in my 'RV' (van lol). I'm not counting spare boxes in storage.