I wanted to throw three ideas out there, mostly for the R builders, but may apply to S builders.
Perrin has just announced a new steering stiffener that fits into the WRX - Legacy universal steering joint to remove the rubber slop. Two members on the LGT forum have tried it and both love it. It's a simple and fast install.
http://perrinperformance.com/i-22342...-lockdown.html
$81
Other LGT forum members pointed out that the new 2014 -2015 OEM STI universal steering joint is a solid joint, no rubber, and it swaps perfectly for the older WRX and LGT universal. Same spline count, same length.
The install is a little more involved but would be a piece of cake during an 818 build. 2015 STI U Joint: 34170VA030 . $197 msrp.
And finally, there is a company making quick turn Subaru steering columns. 2 turns lock to lock! Without powersteering the S builders are probably going to hate it for daily driving. It might be great for R builders though.
http://www.landefabrication.com/steering.html