At lower power levels there will be more crossover distortion and noise, relative to the signal. Is that what you're referring to? Yes I did miss that, but still isn't bad. Extrapolating the the worst graph, figure 25, shows only 0.06% THD+N at 10mW (hardly audible at any frequency through an inefficient, high quality speaker, let alone, at the ultrasonic frequency of 20kHz).
That needs to be put into perspective. What sort of dynamic range does the source have? Suppose it's a CD (vinyl will be much worse) and you've got the volume set to a reasonable level, yet the output is low because a quiet part of the music is playing, there'll be more distortion due to the quantisation error of the DAC, than the amplifier, at those low power levels.
Crossover distortion, you figured it out #1. Now, you seem to be missing it's importance and consequences with regard to music, how we hear, and signal power at different frequencies which pertains to #2. So, I went through the trouble of setting up this little illustration & audio clip. I deliberately chosen cheap pop-rock recording, normal CD quality, originally taken from a cheap .mp3. No fancy soft and loud classical music with wide dynamic range.
See illustration and optional listen to 2 second clip.
As you can see, at the higher frequencies, the audio power is a fraction that of the low frequency bass drum, yet, it still sounds as loud to our ears. In fact, looking at that full power 50 watt signal where the high hat cymbal drums mixed in, which you can hear in the audio, is recorded at full volume. No tricks, yet, the audio power of the above 8Khz signal, well within .mp3 and 16 bit 44.1k audio, has only peaked at 0.7watts and still has definition at 0.06watts. According to TI's specs, lower power and higher frequencies is this IC's weak spot. (Hint: When testing aligning audio systems, Pink noise is used instead of white noise... Now what's special about the 'Pink Noise')
What would happen if I want to lower my volume at 12 watts today, not full blast 50. The first cymbal strike would go from 0.7w down to 0.17w and the second would be down at 0.015w. (I can still clearly hear both High Hat cymbals in this song on my equipment at 12w, 50w and full 250w, though I don't own any audio equipment which shows any cross-over distortion on my scope...)
Remember, crossover distortion is not a slight smooth angular bend or deformation along the full signal voltage in the output signal vs the input signal. It is 2 small 'voids' where neither the NPN or PNP output transistors are driving the output with anything for a short time making a flat linear void where these small wattage signals can sit inside. For the most part, depending on how bad the crossover distortion is and how temperature of the IC amp usually shifts that about makes this IC great for box radios, some TVs, ghetto-blasters, compact all in 1 systems, but I find this un-acceptable for high fidelity solutions. Especially that enough Class B and Class AB designs exist which can do better, except that the ones without such distortion tend to get hot and need a big heatsink. And if you want peak minimal distortion at low power, and a bit of linearity loss at full power, but still no sign of any small signal being chewed up by the big bass drum strikes, Class A amps are the way to go.
This lastly brings me to Class D amps. In theory, a properly designed Class D amp shouldn't have this problem. In an attempt to visualize the working mechanics of a class D amp, The crossover problems should be gone, but, what seems to happen is as the output power goes up, refinement transfer of the source signal does get sloppy, or worse. I do have a few Ideas on how to design a clean musical class D amp at all power levels, but, it means using expensive GAN fets for speed and low rds figures and FPGA components and building everything from scratch the amp would only have digital in.