This isn't much of a guide, but a general tip, something I use anytime possible.

On the honda f4i (and many other bikes) you can remove the clutch cover, and remove the clutch arm that comes out of the case. Then you can cut the arm in half, and then weld in a piece of steel to extend it and make it longer, which makes your clutch pull easier!

The f4i you are limited to only going at MOST 1/2", actually if you go exactly 1/2", when you put the cover on, you gotta kinda force the arm past the frame.

If you want to do it to another bike, and have more room to spare, you shouldn't have any problems going 3/4" possibly even a lil further (you just don't want to rnu out of clutch freeplay at the lever!)

On my f4i, I ran both the 1/2" extension, AND a MSR raptor EZ pull lever together. I 1 fingered my clutch all day, working it in wheelies often, with zero fatigue.

I even extended it on my old Honda Crf150f trail bike. It had a really easy clutch anyways from the factory since it was a low powered bike, but I still added 1/2", and it was buttery smooth.

note, my f4i still had OVER half its freeplay left with my setup! I was still able to run my levers how I like them (only having to pull my clutch in HALF way to the bar and have it fully disengaged

First pic is my 150f clutch arm when I was welding it. 2nd pic is my f4i I'm currently building's arm, I didn't care how it looked, so I just had a friend lay 2 beads and I didn't clean them up, just spray painted it, and last pic is how I had my old f4i setup. I always covered my hand brake and clutch with 1 finger, even if I was just cruising the streets, it was 2nd nature to me, and my setup was super comfortable, and my clutch was super easy to pull.
this is a pic of my 150f's arm when I was extending it

 

Mo leverage!

I dunno man. The only exercise I get is grabbing the brake & clutch.

 

In all honesty, for general riding (cruising the streets), I don't think anyone would ever get finger fatigue and possibly have it affect their riding haha. It still is nice to have though, even if not needed. But of course it's not for everyone (I don't expect people to go out and yank their clutch cover off, and go get this thing welded just to have a "Caddilac" clutch haha!

For stunting, imo it is CRUCIAL! I'm not talking just regular straight line wheelies, pop it up and ride them for blocks/miles. But when working the clutch in circle wheelies and stuff (especially on stock gearing eek!) it is a life saver. 10 ish years ago before I did this, when I was learning to stunt, I'd get arm pump just from my clutch usage in only a few minutes.