I've been trying to trace down a mysterious reduction in the flow I can achieve. Since recording this flow test video where I successfully achieved a nominal 30 mm³/s (almost surely with underextrusion, but with no skipping or warping), something happened whereby I'm no longer able to reproduce it.
Shortly after that was recorded, I discovered a burnt-out XT60 connector between the power supply and printer, and replaced it. That made a lot of voltage sag issues (fans slowing down when heaters turned on, etc.) go away, and I'm wondering how it might affect temperature measurement and indirectly flow.
Could the thermistor voltage have been affected by undervoltage/limited current availability from the power supply, and if so, how would that manifest? Hotend (including thermistor) is stock Ender 3. The controller board is SKR E3 Mini V2. Naively, I would expect that if there was actually reduced voltage on the (3.3V?) line feeding into the thermistor, that would appear as higher resistance, and thus lower temperature, driving the controller to heat it well above the requeste temperature, but I'm not sure if that plausibly could have happened.