MDBT42Q page documentation clarification needed

Thanks @Wilberforce for the source links as that helps cement the h/w count as specified in the note on the module page.

Thanks @allObjects for the narrative.

'the choices of pins is limited to what these 3 SPI hardware implemented appliances define to be usable'

and, that is what I'm attempting to understand, which are the usable hardware pins?

If I view the color key, green for SPI, for the Pico

http://www.espruino.com/Pico

I am able to determine the three hardware SPI 'appliance' access pin numbers. (Note there isn't software SPI or I2C for the Pico STM chip)

As pointed out by the source code from links in #5 there is only one hardware SPI. But viewing the color key of the MDBT42Q, there isn't a color reference similarly to the Pico diagram.

Could it be that: as pointed out in #4 the CPU acts as the appliance for s/w defined SPI, and as internally the one h/w SPI 'appliance' needs to be wired (electrically) to the breakout board pins, that as long as there aren't any naming conflicts, may be wired to any three GPIO pins, thus no need for the green color key reference, as this would clutter the diagram and subject to how configured by the user code? (unlike the yellow key USART pin designations that apparently must be physically/electrically connected to only those pins)