Possible data corruption when sending way too fast (Teensy 4)

[GIPdA]

Sending multiple packets without delay (500us-1ms) might lead to data corruption. The lib is supposed to wait before sending to avoid that, so tests are needed. See ZetaRf::waitUntilOutOfTx.
Seen on Teensy 4. These being so fast, might need to add a small delay before or after.
Workaround: add a 1ms delay after or before sending. No less than 500us.