Hello, is there any documentation regarding the Looper capabilities in the H9000? for instance: Can I use several looper instances at the same time? Can I process the Looper audio while using the Looper(s)? – Thanks

You can certainly use multiple instances of a looper within an FX chain (or in separate FX chains) and then process the looped audio with other algorithms. 

Is there something specific you are trying to achieve? There are many routing possibilities that you can accomplish with the H9k if you want to have multiple instances of loopers being processed by different FX chains etc.