Yes, you can. I'll list the general steps below, let me know if you have any questions:
1. Unlock bootloader first by following the guide here.
2. Then, flash the GMS-less recovery.img by doing:
adb reboot bootloader
fastboot flash recovery recovery.img
3. After that, reboot your Pro1-X to recovery mode. On dead Android logo, use button combo : Power + Volume Up
adb reboot recovery
4. Use Volume buttons to navigate the menu to select "Apply update from ADB", and use power button to select.
5. We will now use ADB sideload to flash the "“merged-qssi_bengal-ot