The controls fit just fine.
I really enjoy my finger throttle. I was in the same position as you last year and I don't regret going with it. I haven't hit any branches, I haven't had any safety concerns and I like the positions I am in with the finger throttle. It took me awhile to feel comfortable doing certain things because having a full grip on the bars feels different but once you get the feel, the positions that can be uncomfortable with the thumb throttle, such as right hand sidehilling, feel more natural and the positions where the thumb throttle feel good feel the same or better.
The only downfall with the throttle is that dependent and where you have it positioned, sitting and riding feels like you have ape-hanger style bars. What I mean by this is my throttle is most comfortable, when I'm standing, facing almost straight down. So when I am sitting I have to wrap my wrist around the bars to reach it. I'm okay with this because I don't spend much time riding while sitting.
Another semi-downfall is the price, but in my opinion you get what you pay for and the quality of my kit was ??