Reply to Traktor Control S4 Scratch Upgrade Kit, Other Mixers

I just got home the free Traktor Control Scratch S4 upgrade kit which was a nice surprise.

However, the package said that this is for S4 only. I could not find anything inside the included documentation that was a generic TP2 Scratch manual. But could this be used with a mixer like Pioneer DJM900 that supports Scratch, or similar mixers?

Do I need to get a whole new Scratch kit just to handle those cases, could neither find another upgrade path? Kind of not fun spending $500+ to just get this feature in case I show up in a club and they have a nice DJM900 or similar system for hookup. Thx for any info.