You can't hit it in an non-FPV with the default setting, true. By default it's set to 6K RPM like the limiter. From what I see of the FPV Cluster though, the limit is higher @6.25K RPM.
I have adjusted mine (it's an OBD2 writable setting, so no need for direct access to the EEPROM) to go off at 5.25K RPM and I can certainly "hit it" and use it to let me know when to shift up.
Whoever said what's in that quote thinks it's an on-off thing, and not adjustable, probably only fiddled with the known As-Built OBD flags - which is where the on-off part is. The adjustable setting is not part of the As-Built data, so they probably never found it while they were fiddling.
