Well you’re wrong… this is not a “democracy” and im sure Supermicro wouldn’t like to see “You can add whatever you want…”
Damm since 2016 and not even one “brain” figured it out… thus very odd since you can add all real easy humm?
First of all there an embedded hw monitor controller on every motherboard, you’re assuming SP uses same model of IC and hw controller routines for all those motherboard models. Second, almost impossible to add new features to the bios code, you dont have available the necessary tools/code to work with.
Third, this is mostly server class motherboards with custom layouts and designs from an OEM, and they sensors behaviour could be linked/dependent to more specific co-processors/ICs controllers, like IPMI for ex.
What you can do, is search for related options/strings in bios, that can be locked to user visibility and it maybe can be turn on to user visibility, regardless what would result in the motherboard behaviour, it can work or not.
Lead versions of the AMI AMIBCP tool can be useful to such task.
An alternative tool is presented here, the UEFI Editor
Good luck.