Even without LOC, there's also TXT. In my work lab (size of a medium DC, tonnes of devices from a variety of vendors) we used formatted TXT records to store things like: rack elevations, host/port for serial access server, switched power outlet info, reservation status, loan / return info and more. With this and cnames for rack numbers/elevations, with simple scripts we could do more than either a free-but-clunky or a decent-but-expensive DC management system could, from CLI, and quicker.

A reasonable compromise might be to use the HINFO and RP records? The latter even has a reference to a name where a TXT record can be placed with additional information, if necessary.