Okay,

the technique worked a treat although while the mel script allows me to replicate what I've done again, there is still no control over the number of coils/loops. If you made 8 by using the isoparm technique, you end up with 8 because that's how you made it. This is linked to the cv that is used for extrusion. I'll look into the script a bit and see what I can come up with although I'm not a mel person.