On: Fire hazard of WHY2025 badge due to 18650 Li-Ion cells

[burnt-resistor]

Why the fuck didn't they just use say 4 safe(r) CR2032s or simply have only +5V USB-C power in?

They could've eliminated most of the risk by simply ripping the 18650 holders off the badges and rely on USB power.

[Zak → burnt-resistor]

You are proposing replacing a ~20Wh battery with a 2.8Wh battery. The maximum current draw from button cells is also likely inadequate for the application.