I’ve been working with my Pico Display Pack and noticed something that is important for other customers to know. There is a conflict between the pins used on the Display Pack and SPI1: SPI1 RX (aka SPI1 MISO) can only be configured on GP8 (pin 11) or GP12 (pin 16), both of which are used by the display pack.
Since the pack uses SPI0, this means you may have a problem if you also want to use SPI1. GP-12 (pin 16) is SW_A on the display pack so if you don’t push the button, you can make SPI1 work.
A humble suggestion to Pimoroni: on a future revision of this board move SW_A to a pin that doesn’t conflict with SPI1.