Running CPY 5.3.0 I'm trying to use SPI bus 1 which is mapped to D11-D13 in the pins config here:
https://github.com/adafruit/circuitpython/blob/main/ports/mimxrt10xx/boards/imxrt1020_evk/pins.c#L19-L21
Here the excerpt from the datasheet:

I defined my SPI bus like so:
spi = busio.SPI(clock=board.D13,MOSI=board.D12,MISO=board.D11)

D12/GPIO_AD_B0_13 is designated as "LPSPI1_SDI" which I have to assume is Secondary Device Input aka MOSI so that sounds correct to me but CPY complains that its an invalid SPI pin selection.

I reverse MISO and MOSI it does not complain but posts:
common_hal_busio_spi_write: status 400

I can not test anything higher than 5.3 unfortunately as that seems to crash, the CPY drive never comes up.