Ah that's incredibly helpful! I was thinking about it all wrong...
So the idea is that, for example, if 1500g of tension puts you at 6" length then after some numbers of hours 1500g will put you at more than 6'' of length in the extender, correct?
So 7.2'' is two bars of tension for me. The idea is that I keep using this many rods until I can see all four bars and then that's when I add another small rod, right?
Always keep at max tension by using the adjustments. You don't have to "wait" till you are at no tension to add bars. Do your max bars and keep cranking it down as you stretch out. If you hit the max on the adjustments that's when you add a bar
Is it really that easy, though? I mean, if one were to spend 5000 hours in the extender, for example, could you reasonably expect a 3'' gain in erect length? (I think your stretched length would be much more than this).