I am just starting to skim through the published specifications for the Pi Pico. At a casual glance the IO drive strength looks quite a bit stiffer than what I am accustomed to seeing on other MCUs.
The output HI drive IV curve is given as:
Contrast the drive strength of the Pico with the drive strength of a PIC16 as:
I am genuinely unsure if a Pico would even survive driving a shorted load. Which is certainly not hard to do miswiring on a breadboard.
When I do get a Pico I will have to measure what the short-circuit current of an IO pin is, even on the 2 mA drive strength setting.