Don't overthink it. Any decent rear bracket like a Steeda makes a huge difference. I did it all. Bracket, weighted knob, Whitline bushing and MGW arm bushing. They all helped some. Between the bracket and the weighted knob, they helped the most. It wads about as good as any remote shifter will ever get like that.
The shim mod can actually promote misalignment rather than reverse it.
I used this setup to pound out over 100 dragstrip passes. pretty solid, even if the addup was close to what a full shifter would have cost.
2014 Premium GT, SGM, Brembo, Auto, Tech, Comfort, etc. GT500s, Steeda UCA, VMP auto tune, 100 shot on BBR tune, best et: 11.38 at 120.85
2012 GT, Candy Red, Brembo, 3.73, Tech, Comfort, etc. Procal tune, Roush upper, UMI LCAs, Steeda red bracket, GT500s, 28X10X16 Hoosier slicks, best et: 11.91 at 115.23 RIP