I just transitioned from 744 FO to 742 Capt. I had a significant amount of raw data ILS practice, mainly due to 1 Capt I often flew with who insisted I fly raw data when the weather was good (and, later on, even at night or reasonable IFR).
As a result, my transition to steam gauges was a snap, even after 7 years of glass.
If the Captain retains his FD and ND while the FO turns his off and/or goes to ILS mode, there should not be a significant increase in workload for the Capt.