Sycamore - slightly long-winded thread creep but your description of Whirly 10 'computer out' brought back memories of a Master Pilot returning to helos after original Whirly 4 ops. (Whirlwind Mk4 was piston engined and required a deal of co-ordination of twist-grip throttle and collective to maintain the narrow band of correct rotor revs)
On the 10 'normal' flying had 'computer' control to allow automatic throttle compensation for collective movement. If you selected 'computer out' you reverted to twist-grip co-ordination. Said Master Pilot was never the most accurate in the hover when computer-in but the moment he went computer-out, it all calmed down and the rotor revs never varied!!