Thanks for your pointers.
Golden rivett: Yes you have a good point that turning the pack off is a quick easy way ( as long as X bleed isn't open) to stop more smoke/smell entering the cabin. However if it was smoke that had already entered the cabin and causing pax breathing difficulties then you may still want to remove it.
Lomapaseo: Please correct me if I'm wrong but are you saying that as the compressor blade tip makes contact with the abradable seal as the seal is worn down ( as it should do in this situation) it could produce a temporary burning smell/smoke. Once it's worn down, which shouldn't take long there is enough blade tip clearence now that there is no more burning smell/smoke produced so if all other parameters are correct it can be run at idle and therefore not require an inflight shutdown?