For the most part I stay out of this debate, it's like an oil or tire thread..... however, there is no debate that tapered rollers are robust enough to hide/withstand/mask the causes for the decel wobble. Practically every bike you know (only a couple of exceptions come factory equipped with tapered rollers) use this exact same ball bearing setup. Practically every bike should have them checked and retorqued after a short break-in period (even tapered rollers), and Yamahas in particular (my opinion).
Most bikes if not all except Yamaha, have a torque spec for the ball bearings of 16 ft. lbs., and FYI, Kawasaki Versys 1000 says initial torque 48 ft. lbs., back off, final torque of 21. Yamaha says 13 ft. lbs., and IMHO, I've always maintained this should be higher, in line with other bikes using the same ball bearings.... and then there's the older method of tightening and measuring steering effort (~2 ft. lbs.). I've owned 2 FJR's and worked on many, and it seems every one is loose at that first service. So, those with wobble, try torquing up your steering head first, then see what you got. If you want to go a step further, regrease them as grease was used sparingly at the factory.
Given most say the wobble is on decel at lower speeds is only felt when taking the hands off the bars or a very light grip, I can't imagine this is causing or will cause any wear/harm to anything else (fork seals, wheel bearings, etc.). Obviously, the wobble bothers some and they want it gone, and tapered rollers will likely do that. But you didn't solve anything about the causes, whatever they may be. Which is OK, it's all harmonics.
I never have had any wobble on either of my FJR's, but I did service the ball bearings (grease, re-torque to~16). I will say I just noticed a vibration in my handlebars on decel on my Honda CBF..... 24k miles. I believe it is the front tire wearing down (6k miles), Avon Spirit ST, and as I rub my hand over the tire back and forth, I can feel it's not perfect and that tire is wearing very evenly... so that's my conclusion, to be fixed with a new tire once this one is worn out. It's minor, it's not a big concern.
If you don't want to change your bearings, couple things you can do..... loosen your lower pinch bolts and jounce the forks to correct any misalignment upper to lower triple clamp. Service the head bearings with grease and re-torque (16). Loosen the pinch bolts on the right hand axle and jounce your front end.... this should self-align the right fork (service manual is wrong, fork should be straight and in natural alignment). Check your tires for wear by rubbing your hand over them.
I'm done now, make your choices and be happy.
