Regardless, let me point out some things that are important about measurements (in no particular order and off the top of my head):
1. Measurements without comprehensive details about what was used to make the measurements and how it was set up, along with control tests, need to be treated with a huge grain of salt.
2. Even measurements using high-grade analysers require very carefully repeated tests and analysis to mean anything, as the analysers have many settings which can change the results. Even something as simple as a wire crossing nearby a power source or cable can change the results. Likewise, just changing the weighting of a measurement (eg: to A-weighting) will change the results considerably. A single spurious tone at one point in the entire frequency range will change a measurement, even if all it affects is one frequency to a degree that is effectively inaudible.
3. Measurements from RMAA are made using frequency sweeps. IMD distortion is measured using a pre-set pair of tones. Music does not consist of frequency sweeps or a single pair of pre-set tones and very likely the device will be used with components that have very different electrical characteristics than an analyser or sound card. That is: An amp's performance into an analyser with sweeps is often different to how it will perform with headphones with music playing, which provide a completely different load.
4. Negative feedback in circuits gives you better numbers, but increases distortion in the time domain, which required extremely expensive equipment to measure. It does impressive-looking numbers though.
5. Manufacturers don't provide more than basic (and essentially useless) measurements because the numbers can be misleading for the above reasons and don't relate to our experience when listening. Sometimes they provide the most impressive numbers in the most impressive weighting at the most impressive frequency to promote their products (and don't put the less impressive ones).
6. Unless measurements can be connected back to our listening experience, they don't tell us anything very useful. They are more useful in the reverse, when trying to track down the reasons for our experiences when listening with a product, such as why certain music sounds better on some headphones than others because of differences in the frequency response.