I'm the creator, good question. They're ridden, not matched. Each stem gets its own fixed level in the scene code. Then one shared gain brings the full mix to -20 LUFS, so the stems still sum to the mix exactly. Measured with ffmpeg ebur128 across the 6 scenes:

• bed: -24.9 to -22.9 LUFS
• air: -24.7 to -22.4
• detail: -32.5 to -28.0
• presence: -29.4 to -26.8
• full mixes: -20.0, true peak -8.5 to -6.1 dBTP

So bed and air are the loudest layers, and detail/presence sit 4-8 dB lower by design. (The synthesis code was written with AI assistance.)