Steam's charge limit goes through SteamOS Manager's BatteryChargeLimit1,
and upstream steam-frame.toml configures no backend for it. The Frame's
battery is a max1720x fuel gauge with no charge_control_end_threshold.
Conclusion: don't build it yet; read-only headset checks are listed.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>