Blackmagic Disk Speed Test results
Average Write: 40MB/s
Average Read: 143MB/s
Note - the thumb drive got almost untouchably hot while directly connected via USB-C but only warm while using the Apple USB-A to USB-C adapter. Speeds remained on average the same whether using the Apple adapter or not.
Test speed is an average of 10 results using running Blackmagic Disk Speed Test 3.1 and macOS 10.13 Beta 2 (17A291j) on a 2017 MacBookPro14,3