The amplification at three different input levels is standard. Simple digital aids only have two input levels. Three input levels mean compression with two kneepoints.
For music, the levels would need to be higher, though. You have almost no control in the area above 80 dB (which doesn´t matter for speech, above 80 dB is yelling, but it matters much for music).
Using no compression is bad. Consider an amplification of 20 db at 3 kHz. If your mpo is set at 105 dB, all input-signals above 85 dB will make your aid hit hard agains the mpo (which means: compression ratio infinity). The rule of thumb is: Use less amplification to allow for less compression. The values used for the live-music-plus program are a good starting point.
In my experience, compression ratio below 1.5 sounds pretty good for music. I have tried a program with no compression. Drums sound pretty hard then, but the sweet spot for listening is extremely narrow then.
Looking forward to your report!