It can be tricky sometimes for sure... If you're not having any in-between the quiet or distorted, then I'd start by checking out the placement.
I see ALL THE TIME where people only have 2 of the 4 X-brace magnets actually holding the TWA in place. This won't work well because it rarely creates enough downward pressure for a firm connection. If the magnets grab closer to the transducer on the bottom, you may be okay.. but if it's on the other end, your tone will sound really bad since the transducer is basically bouncing on the back of the guitar. Try a slightly different position on the back to see if it helps.
Also, check your preamp settings. Try adjusting the EQ lower and boosting the Master Gain or vice versa to see if you can find a warmer tone.
If you want some more help with it. Fill out a support ticket and I'll be in touch to walk you through some troubleshooting.
The overall position will hugely affect the tone. That's why it's important to find the spot on your guitar where it resonates the best and sits flat. Make sure the cone is not against any of the bracings inside the body, this will overdrive the transducer and kill your batteries.
There's enough flex in the transducer arm and cone that you can nudge it towards the neck and help to flex the cone flatter against the back, but this may not be effective with a more extreme arch.
I see lots of people offset their TWA either for a flatter and better connection, or due to sensitive pickups causing feedback. Make sure that another area of the lower bout doesn't sound and fit better. Our installation guidelines are mainly starting suggestions, but you also have to make it work for the guitar you're using it with.
I remember when I first set up my Taylor. It was very muddy sounding.
Once I repositioned it (a few times) and ended up putting it closer to the output jack, it really came to life. The nudge trick really helps to make sure the cone is flat, too.