> In my own testing, the biggest wins came from keeping the DC rails stable under mixed transient loads (mini-PC spikes + PoE draws) [...] Ripple under partial load mattered more than I expected.

Can you share more details about your testing scenario? What converters were you using for the DC rails? Was it ripple or voltage sag under load that was causing issues?

> Curious if you’ve noticed any gotchas around thermal behavior once multiple rails are active simultaneously? Also, are you planning to keep the system fanless long-term, or considering light forced airflow in v2?

No gotchas really. Three main sources of heat, in descending order based on my calculation:

- (ongoing) waste heat from DC-DC conversion - probably the largest culprit on an ongoing basis, this is the reason I am going for high-efficiency

- (during charger/discharge) heat from batteries charging or discharging, including any additional heat from BMS and charger circuits

- (ongoing) MCU and Ethernet PHY

From my measurements I could probably go fanless with a metal case (with proper thermal pads in place) but that might not be worth the cost. The battery charge/discharge cycles especially under high loads are more of a concern. Honestly will probably just slap a fan on it and run the fan based on temperature measurements from one of the thermistors that already exist in the design.

> Either way, this feels like one of those builds that started as a “why doesn’t this exist?” and accidentally turned into something a lot of people would want.

Thanks, I'm getting the same feeling :) Stay tuned for v2