I think RV-12 throttles had a tendency to slip because of the spring tension on the Bing carbs on Rotax engines - hence the Vernier. I installed a Mcfarlane vernier throttle cable on my RV-14 but purely for its function.
(I have a Superior XP400 engine and for this engine ONLY, I would recommend adding an extra 2" to the cable length over the standard Vans cable length and this engine will also require fabricating a new throttle bracket.)
RV-14A Builder - kit #136
N314KC - First flight Mar 8, 2017, Phase I compl Apr 3, 2017, >180 hrs
Sport Pilot (weight-shift control) - Airborne XT912
Dues paid 11/2017