It is not an urban legend that some USB device don’t work well.
However, skip my comments. You seem to have found successful methods to implement USB. So I’d suggest writing a forum Resource, perhaps titled;
Path to success with USB attached storage
You can then include that using USAP helps performance. That it appears FreeBSD, (used in TrueNAS Core), has worse USB support than Linux, (used in TrueNAS SCALE).
Write it once, and reference it as needed or desired.
It is just that we see in these forums people using USB with trouble. For example, just today;
