This read-only TruthValue reports whether bit error injection is active for this running BERT test stream, the live counterpart to the writable config-side setting, per its description. An administrator checks this to confirm that error injection is genuinely engaged for the currently running test, which matters when validating alarm behavior in real time. For example, an operator waiting for an alarm to trigger would first confirm bertTestStreamErrInjectEnabled reads true before concluding an alarm failure was a real problem rather than injection simply not being active.