[Closed] Rear mechs - adjustable spring tension?

I know older XT mechs used to have adjustable tension but is this a feature of any of the newer models? I'm currently running an SLX shadow mech and shifter - outers are fitted with Middleburn cable oilers so shifting is plenty smooth enough but the mech spring tension is really strong. I generally have problems in the winter as the end of my thumb tends to split in the cold weather but the last 2 weeks off work and nice long rides most days have left my right thumb wrecked. Don't really want to go down the gripshift route and not sure if rapid rise is the answer (I'd just end up cursing on the downhills instead of the ups 🙄 ).