From perusing David Eduardo's radio history website, it seems that Arbitron classified Format 41 stations as "Vocal Easy Listening" rather than Soft AC.
In Detroit, our Format 41 station was 93.1 WLTI, which switched from Urban WDRQ in April 1985. At the time Detroit's adult-music field was crowded, with three stations splitting the mainstream AC listening pie (WNIC, WOMC and WMJC) and two beautiful music stations, the very highly-rated WJOI (Bonneville format) and the nearly invisible CKEZ (former CKLW-FM) in Windsor (KalaMusic). If memory serves, "W-Lite" didn't have much ratings success until they dropped the satellite feed and went to local personalities with a locally programmed mix similar to Format 41 around 1987 or so. During the early '90s it was often the top-rated AC station in town as the music slowly became more contemporary.
In the summer of 1996 it became WDRQ again, with a rhythmic AC format that evolved into rhythmic leaning CHR over the next couple of years. It's been "Doug FM" (a Jack FM clone) since April Fool's Day 2005.