I have a prop shield and both Teensy 3.2 and Teensy 4.0, but I have more of the latter, it's faster, etc. I haven't found any mention of the 4.0 used in association with the prop shield (I'm using the IMU sensors, primarily), so thought I'd inquire.
Orientation: 214.86 23.41 101.84
Orientation: 215.54 24.09 101.47
Orientation: 216.09 24.82 101.02
Orientation: 216.51 25.65 100.47
Orientation: 216.81 26.57 99.82
Orientation: 217.04 27.54 99.12
Orientation: 217.22 28.47 98.42
Start Big write of 2048000 Bytes.........................
Big write /0_2MBfile.txt took 5.72 Sec for 2048000 Bytes : file3.size()=2048000
Big write KBytes per second 358.31
Bytes Used: 2060288, Bytes Total:8388608
printDirectory SPI_DISK
--------------
FILE 0_2MBfile.txt 2048000
0 dirs with 1 files of Size 2048000 Bytes
Total 1 files of Size 2048000 Bytes
Bytes Used: 2060288, Bytes Total:8388608