By default, the program writes the split files using the original filename, incrementing the track number by one for each successive file. This is all good, except that the unchangeable default starting track number is 00.
After a recent use of the program (probably eight months ago) I emailed their support site about this, not expecting anything to come of it because after all I was using the free version and had not signed up for their priority support or anything.
Last night I used the program again -- and the annoyance (I wouldn't go so far as to call it a bug, just a programming oversight) had been fixed. I sent them an email thanking them, they responded within a few hours. Call me impressed!
tanstaafl.