> Any decent GNSS receiver you can purchase in the US will be able to receive all 4 major global constellations. I know this cause I work with them everyday.

All common handset devices used in CONUS (every iphone, android phone, etc) will ignore BeiDou signals. Would love if someone hacked the GNSS firmware to make it usable, but haven't seen it happen yet. If you travel outside the CONUS geofence these signals will show on the device, but FCC has some mandate requesting a block, so it's blocked.