It's a good question. None of my (Gossen) meter leashes are that long but they are all long enough to be slightly annoying. With my smaller (Gossen Digital) meter , I wear the lanyard around my neck an keep the meter in the shirt pocket. This keep the meter from banging into camera but invariably, the meter lanyard and the camera neck straps get tangled up. I recently replaced the lanyard on one of my larger (Gossen LunaPro SBC) meters with a wrist strap....but I'm not sure that I like this situation either. Alternately, I replaced the neck strap on one of my smaller, lighter cameras with a wrist leash and added a sturdy grip to the camera.
I'd like to be able to keep the camera and the meter on some kind of leash with out them banging into each other while I'm walking and not using either of them.