An inkjet printer assembly includes a cartridge which has a pagewidth printhead integrated circuit (IC) and a printhead auxiliary member. The auxiliary member is operatively rotatable between a platen position, to support a printing medium proximate the IC, a blotting position, to blot the printhead IC, and a capping position, to cap the printhead IC. The assembly also includes a cradle configured to receive the cartridge such that the printhead IC is adjacent a media feed path. The cradle has a transmission assembly arranged selectively to engage and rotate the printhead auxiliary member. The assembly also includes a controller arranged to determine a performance characteristic of the cartridge and to operate said transmission assembly, printhead IC and printhead auxiliary member in response to the determined performance characteristic.