My old job at a Bell CSF involved doing a Maintenance Flight before and after a helicopter was recieved for maintenance, we would take all paramenters, idle, hover, flight, power check, control rigging, and Autorotation RPM, etc. etc. I have probably flown 40 different JetRangers and some get a needle split in Auto but some don't, at first I thought that wasn't right, but the mechanics said that it was ok as long as when you where on the ground, when you shut the engine down the needles would split, if they didn't then there were problems, but this was on engine shutdown.
In flight we have never made a discrepancy of the needles not splitting.