Is there any support for fast m.2 cat20 4g & 5g wireless cards, such as Sierra Wireless EM9191 https://www.sierrawireless.com/iot-modules/5g-modules/em9191/ ?
You would have to use right key m.2 to minipcie adapter and really new kernel but there were reports to make EM7565 working so the previous model. If I were you I would check which kernel added support for that card and check some development branches if they have the patches already.
And EM9191 is still really expensive. Maybe get EM7565