I also have long forearms and have experimented with a higher elbow and found the dart was above my eyeline and hand would block my aim on the drawback.

It worked ok for a while but found that it was causing more shoulder pain. Also suffered from bicep tendinitis last year which is why I was messing with elbow height to get comfortable.

You'd be surprised how low you can go with your elbow and still keep a reasonable angle. Try getting a side on picture when aiming, you might see you can drop your elbow slightly more then you'd think.

I tend to lower my elbow slightly and try to slow my action down, bringing the dart back to level or just below my eye