Usually such a switch function that affects the tape lifters on other sets is commonly called a "search" function. The tape lifters pull the tape away from the heads during fast functions such as: fast forward, rewind and pause, to prevent head wear. A tape lifter disable is really only useful either when editing or moving the tape by hand to hear what is on the tape at a precise point; or to hear tape output during fast wind or rewind to get to a point where the program, song, or selection ends.
Hopefully Sony's implementation of the tape lifter disable switch also reduces the audio level by 10 dB or 20 dB to make sure its use doesn't inadvertently blow out the tweeters and/or woofers in your system, by applying supersonic or subsonic audio quite when at high wind speeds - at normally high audio levels... YMMV..
-Steven L. Bender