The limited number of temperature values is intentional, as far as TrueNAS is concerned.
https://forums.truenas.com/t/truenas-scale-24-10-2-is-now-available/32410/2
i5-1240P has 12 physical cores, where 4 are performance cores with SMT that brings the total logical cores to 16. This means the expected (and shown) behavior is 12 temperature values and 16 usage values.