A long time ago he was asked this question, specifically regarding why there was two versions of SOS. He said for every song he records, he would have at least 3 or 4 versions, from which he would decide (after extensive listening) which version would make the cut. He began this practice with Ngobila, which has 5-6 versions released
Releasing a version for the album and VHS/DVD helped Koffi a lot with sales. The VHS' for Noblesse Oblige and V12 were very popular thanks in part to this. Starting with Danger de Mort - onwards the only difference was elimination of mabanga.
Many years ago I heard alternative versions of Etat civil and Chantou - I've been searching for both since. In the Sur la route de Bercy video, he showcases the alternative version of Non assistance, which was completely different from what made the cut for Attentat. He could probably release multiple full-length albums with just alternative versions of past hits, but he says he doesn't like reminisce in the past.