@jbbz Many thanks for your reply. I was unaware of AAO and, having purchased it, I now enjoy a finer, and linear, response from elevator trim inputs.
I think I was incorrect to state that the Arrow did not suffer from the standard Asobo trim response. I do now think that there is the standard Asobo delay between the initial one-click response and a continual input. However, the animation of the trim wheel movement looks continuous - with no pauses - and that masks the actual behaviour of the trim mechanism.
I've made minimal use of AAO so far, but have transferred 'control' over to AAO for elevator and aileron trims together with rudder axis and it works well.
Thanks for pointing me in this direction.
Regards