OK - a chat with Peake's tech expert confirms my hypothesis.
The chart is designed in reverse, so to speak, and there to support someone who is using an OBDII tool. All the possible OBDII codes that are mandated are listed, with the nearest factory code shown next to it, and then the generic definition.
This winds up giving you the closest approximation of the factory definition for codes that can be correlated. There are many that are not, but that has been discussed before.
Because BMW's diagnostic system is independent of OBDII, there are generic definitions that may be important to other makes that BMW is required by law to include - even if they are never used. The codes you've specifically asked about, for example, represent data that the factory system is likely NOT monitoring or reporting on. Therefore, when code 77 is generated, your OBDII tool would not show the 'high' or 'low' codes.
Bottom line, you would not get more accurate data with an OBDII tool - first because the generic codes are the closest approximation, and second because your BMW only monitors what it monitors, regardless of whether OBDII has a an available code for a particular range of data. If that data is something BMW monitors, it will be reported as a factory code with the nearest OBDII code as required for government inspection.