Q: Caeremoniale Episcoporum 49 mandates that the Bishop should not celebrate in the presence of the Blessed Sacrament Reserved. Does this apply to all episcopal celebrations, or are there exceptions?
A: I don’t agree that CE 49 mandates that the bishop should not celebrate Mass in the presence of the Blessed Sacrament Reserved. Rather, it mandates that he not celebrate Mass on an altar on which sits a tabernacle in which the Blessed Sacrament is reserved. If the tabernacle rests elsewhere in the sanctuary or outside the sanctuary, he may proceed as usual.
I agree that when a bishop presides, it is best not to make recourse to the tabernacle for the celebration of the Mass, but I think that’s not what CE 49 concerns.
Rather, I think that this is a reference to GIRM 315, itself based on Eucharisticum mysterium 55, which says it is more appropriate not to situate a tabernacle on top of an altar where Mass is being celebrated, as was formerly the widespread case, and which GIRM 315 presumes still occasionally happens.
To me, it seems that CE 49 says that if a tabernacle does (inappropriately) rest on top of such an altar, its contents should be transferred to another fitting place at least when the bishop presides for the Mass. CE 49 also recommends that the tabernacle be located apart from the main body in cathedral churches; this further supports its removal from the top of an altar.
GIRM 85 encourages the distribution of holy communion to the people from the hosts consecrated at the same Mass. Although it does not strengthen its case when a bishop presides, the basic principle holds. It fits your basic point that the reserved sacrament plays no essential part in Mass with a bishop, but that’s true of every Mass.