I cannot find one single XIAO 52840 BLE “free” pin that can be used for frequencies above 10khz. All the high speed pins that are NOT limited by Nordic’s datasheet to Low-Frequency (below 10 khz) are used for the QSPI, SPI, i2C, LEDs, battery read, etc already. There are some pins that are High-Frequency, but are not brought out.
(1): bring out some more High-Frequency pins by using a smaller standard pin-spacing (look at the Ebyte 52840 dongle in the photo).
(2): switch some of the High-Frequency pins currently used for trivial operations like LED, battery reading, etc to Low-Frequency pins as to free up some HF pins for the user?
(3) both (1) and (2)