@lassoan, the problem I’m referring to is that the changed behavior of visibility management happens for all rendering modes, not just the multi-volume rendering. Previously (e.g. 4.8.1), the volume selector acted like a radiobutton, where selecting a volume made it visible and the others invisible, which makes sense for renderers that don’t support multiple volume rendering. Now, visibility is sticky with the volume, which makes sense for the multi-volume mode but not for the other modes.