Editing presets live

Point both surfaces at the repo’s version-controlled presets/ and edit a .toml — no rebuild, no relaunch:

# Windows (PowerShell): the app reloads the edited file within ~150 ms
$env:RLX_PRESET_DIR = "./presets"; cargo run -p standalone --release

# ...and every shot in that shell reads the same folder
cargo run -p standalone --example shot -- --preset "Whorl" --out shot.png

For a one-off capture, the flags say it explicitly and need no environment:

# The whole repo library
cargo run -p standalone --example shot -- --presets presets --preset "Whorl" --out a.png

# A single file — --preset is unnecessary, the one-entry library names itself
cargo run -p standalone --example shot -- --preset-file presets/fragment_whorl.toml --out a.png

# Metrics for the repo library rather than the seeded per-user copy
RLX_PRESET_DIR=./presets cargo run -p standalone --example shot -- --report

The app hot-reloads an override folder but never seeds into it (it is yours, not ours), and diagnostics.log / config.toml stay under the per-user app directory. The foobar2000 plugin does not read RLX_PRESET_DIR.