If you use muscle to increase the length of the follow-through, you are NOT doing it right. Cutting it like Stu and going all the way through like Clara Guerrero shouldn't be any difference at all. Accelerating at release, to force more revs, that will use muscles. Increasing ball speed by muscling the swing will also use muscles. Letting the follow-through go higher should not... Your arm is already moving forward at release, then upwards, but without a ball. If you can release the ball, and swing it, following through properly shouldn't make a difference in the use of muscles.
I believe you are right on.
Somehow, to get my arm to go higher, which feels totally and completely unnatural to me btw, it takes force of muscle to keep it going up.
Also, I tend to be bent over close to the lane as I tend to get low on release.
If I am bent over, pulling up with the arm is hard.
If I stand more erect then it is less hard.
But either way, keeping the arm going forward and up takes, for me, effort.
I must not have the timing down yet, so muscle is still involved.
I am doing it wrong, but I am trying.
I will keep working.
Pain is my guide.
Actually, I found a video I did a few years ago where I had a longer pushway with a higher follow through and faster ball speed.
The longer pushaway naturally allowed me to get a higher follow through.
For some reason I got out of this and developed a shorter pushway that resulted in the lower knuckle/curl motion in the follow through.
Now I am back to using a longer pushaway and the follow through is higher.
Check out this video and let me know if this looks more like you want me to be doing: