“The S9 is not class compliant, and thus not working without a driver. On iOs there is no way install drivers. So it’s actually Apple and Pioneer you should be asking about this. Apple is not taking another approach, and the S9 is succeeded by the S11 and the S7, so no chance they will update the firmware. It is what it is, unfortunately.”
Neither statements give me a clear understanding whether a DJM-S9 can be configured to use it as it would be a DJM-S7 mixer for DVS (scratching etc) on iOS.
@anatomia unfortunately, this probably isn’t too helpful now, but Algoriddim does have a list of supported hardware for each OS. While this list is not always completely up to date, it’s a good place to start before committing to an annual subscription. Also djay is available on a monthly subscription.
Just wanted to mention that DJs have reported issues with the upfaders on the S7. They seem to fail pretty regularly and they are soldered on so they are not easily replaced. The S11 on the other hand has better quality upfaders like the S9 which also, if they fail, can just have a replacement fader dropped in and connected to the cable inside. No soldering required. That’s just something to keep in mind. I’ve seen a few DJs on different online forums with practically unusable S7s because the repair time is so long or they’ve sent theirs off for months with poor customer service response from the Pioneer repair center. You may want to save a few more chips and just get the S11…