I never use any of the HDMI cables that come with these devices., I'm glad they didn't stick one in there. I have a box with dozens of HDMI cables that came with my devices. I only use HDMI cables from Monoprice.
As far as it asking you about a couple of channels during setup, how esle is it going to verify it has the right info? In my area there are several cable companies, and during that setup that when it checks a couple of channels, you know you have the right lineup that way.
As far as updates, when I get a new device I expect it to update right away. If a device does not update during the first boot, I am suspect about it because if they are doing their job right, there should be an update with all the recent changes/additions/bug fixes. I would rather the device update right away, then work with some possible issues only to update at some point later to correct them.
The Serial Number is also in the sys info screen. I don't think I've ever looked at the back of the TiVo to get the serial number. I've either looked at the box or looked at the sys info screen. But either way, have the info in small lettering on the device is the norm anyway. It is nothing unusual and a person with good eyesight has no problem reading. But I know I have problems reading the small lettering in dim light which is why I try to avoid those situations as much as possible.
Roamio Pro (5TB Red)
TiVo Mini x4
Roamio Basic(1TB Red)/Roamio Basic refurb(stock drive)
53TB unRAID2--38TB unRAID3--33TB unRAID1a