That FAQ is for the 2000 and 3000 model Replays.

Actual 4000 Replay FAQ

You can turn it on or off by show or as a global preference. I haven’t seen a commercial in months.

The way it works is patented by commercial advance not sonic blue. I think it works by monitoring differences in audio compression levels and black frames. The commercials are recorded with the program, but a index is also made.

When the show is played back the software looks for patterns and automatically skips the section that has the traditional characteristic of a commercial block.