Is there any mileage in using a bridge rectifier in the assumption that the bridge is made from the same material for each diode?
In practice, you will hardly notice any difference from using a bridge or 4 identical diodes with the same current rating. A difference is for high current bridges that are prepared for fastening to a heatsink. Most single diodes are not suited for heatsink cooling.
Bridge usually is smaller than four diodes. I use diodes only if I can't have bridge I neeed, for example we don't have powerful Shottky bridges (but I like them).
You mean they would be dies from the same wafer? No difference for power supplies, might make a difference if using the diodes in some sort of signal-level balanced bridge circuit where matching Vbe matters. Still with individual diodes you can always select for matching properties if you need to.