It's a really interesting alternative for getting something closer to 70mm 6 track magnetic audio into conventional 35mm theaters. The thing is that they didn't think about the large noise associated with multiple optical tracks with no hiss reduction. Thus it was only used and abandoned for Popeye and Dragonslayer with them being reconditioned for Dolby Stereo. It must have had some kind of Paramount association, thus Raiders would be planned and mixed for the new format but converted to Dolby Stereo for the main 35mm release.