I don't have a steering damper on mine, and doubt I'll get one.
However, the stock suspension setup is sort of a blend between the R and the X, so there's too much tail end ride height for good handling. The X version has the 17" rims F&R, and needs more front wheel weight bias for that role. The frames are the same, so the steering geometry is set for the X and wrong for the R. I put the Yamalink on mine, dropped the back end about 1.5 inches total; then put the forks up about 0.625 inch/15.5 mm, and reset the sag. The handling is now very good considering the bike's weight and the stock valving. I don't have them handy, but can give you my compression/rebound settings for both ends. I played with both ends quite a bit before I settled on these. They haven't moved since.
I'm at the point that it handles more than good enough to wait for a suspension redo, when it will get Gold Valves. The only complaint is the high speed damping due to the very rocky area I ride. It's better than most as is. Even as is, I still tend to go faster than most of my riding associates, so getting it too good will just make me wait longer. 8) I dropped the whole KTM EXC-f/EXC concept for just that reason.
Fitting a 12T front will chew the swingarm and/or slider and kill off the chain. I swapped early on to the steel Sunstar 47T rear and left the stock front on, added one roller link and two rivet masters to the original chain and have done fine. Next go round, I may add another few teeth to the back. Be careful of the stock chain rollers: they are hidden and have a tough life. I fitted the ball bearing versions when I did the sprocket thing.
If you ride rock, a Flatland plate is highly recommended, as is the Flatland/EE rear disk guard. The disk guard was picked after I noticed how many times my chain guide had rock hits. Nail-heading a disk could ruin your ride.
I switched to ProTaper 1 1/8 AL bars and the GYT bar mounts, and have Zeta hand guards and levers fitted. Tossing the stock radiator guard and fitting the Flatland version makes it run a lot cooler. Fan seldom comes on now, it used to constantly run with the stock setup.
I have D606 rubber F&R, works for my local terrain so well that I haven't bothered to try anything else. Sometimes I have too much traction. They work on roads during torrential downpours better than many street tires.
Oiol change every 1K, filter every other, run good oil. Mobil1 Racing 4T is what I use, others work. Don't bargain basement the oil: these engines have a very limited oil capacity and need quality lube.