Hey David,
I don't have much experience with coupling a vane to a wheel, but I've always believed they are generally more effective with tiller steering, anyway...
Depending upon your emergency tiller setup, could that be possible with your boat?
Drake, this might apply to you, as well... Have you thought about using an emergency tiller like the one Eric uses on Fiona, taking the control lines to that, instead? (Not being familiar with the Aries you're using, of course - but that's what I might try on a boat like yours, at least with the Sailomat I'm using)
best regards,
Jon