I'm shopping for a distro from a major player (not ampshop) and was surprised to see they offered two different versions of several output panels of the same receptacle type - i.e. L14-20. One version has multi-pole breakers; the other has exactly the same receptacles but untied single pole breakers.
The rationale was that true multi-pole loads needed common trip, but if the L14-20 was used only for 120V loads, single pole non-common trip breakers is acceptable. This is a listed shop so presumably UL/ETL has OK'd this, but I was surprised because this would never fly in a construction setting, and it wouldn't fly for me either - having to keep track of "this is the single-phase only bank" and "this is the OK to use for 208v bank".
Thought that was very curious.