Are there any benefits? No, I don't think so. You might hear a difference between a new and very old (heavily used) 300B, but if they have similar history I doubt anyone could hear any difference at all.
The 5670 uses the two sections very differently, so there is no point at all in matching the sections. The shunt reg half is dominated by the 431 chip, and the driver itself has a bias trimpot so you can set its plate voltage exactly.
