I'd like to use a hAP AC Lite with a Sierra 7455 in a USB adapter.

I'm assuming I'll have to tape some of the pins on the PCI modem, but which ones?

See viewtopic.php?t=186137#p953868

You may also be able to flash the device to the latest firmware using a PC, the use AT!USBSPEED=0 to set USB 2.0 speed.

The hAP ac lite doesn't have a miniPCIe slot. Only USB, and only USB 2.0. The Sierra MC7455 defaults to using USB 3.0.