Okay, made some changes. I decreased the overall saturation boost as you suggested Funcha. Here's my most recent color tweaks:

dv1=mt_lutxy(last,last.Tweak(hue=-90,coring=false,starthue=315,endhue=135),"y",y=2,u=3,v=2)
dv2=last.Tweak(hue=-45,coring=false).SmoothCurve("0-0;255-255","0-0;255-255","0-0;128-128;255-128",dither=100,show=false,interp=0).Tweak(hue=45,coring=false)
dv3=mt_merge(dv2,dv1,last,luma=true,y=2,u=3,v=3)
mt_average(last,dv3,y=2,u=3,v=3)
mt_merge(last,last.Tweak(sat=1.5,coring=false),last,luma=true,y=3,u=3,v=3)
Tweak(hue=-45,coring=false)
SmoothCurve("0-0;128-158;255-255","0-0;128-128;255-235","0-20;128-125;255-255",dither=100,show=false)
Tweak(hue=50,sat=1.1,coring=false)

Feedback is much appreciated.

-G