The TH-K2 has 100 memory channels, or 50 if you use alpha tags. I don't use the alpha tags, and have almost all 100 memories full. Here is my problem: when reading from the radio, Chirp will only read the first 50 channels. Any attempt to change the values in the "Memories Memory Range" is immediately changed back to 50 channels. There doesn't seem to be any way to get Chirp to read all the channels.
The problem is that we don't have any way of probing from the computer side whether or not the radio is in 50 or 100 channel mode. On another Kenwood radio that had similar behavior, I tried various methods of trying to guess based on the contents of the memories, but it was pretty much always wrong for someone and/or provided quirky user behavior.
I think it's infinitely more common to have your Alpha tags enabled these days, so I think CHIRP taking that assumption is pretty reasonable, in the absence of other options...
--Dan