A little unscrewing is needed still for better preformenc.
I wouldn't add more then one o ring bellow as I'm afraid the axis will become unstable on the plastic threads.
Now it's fine,if you want more without unscrewing then you can add adjustable nut on Ithaka or Pene
so it push more the CT,but I prefer it as so.
with little unscrewing you can lower CT enough
To close spring and get to the solid part of the axis.
But it's better and not like before,you have the two o rings of CT post inside The SS sleeve of CT.
That's great. And maybe 2 orings would leave a gap also in solid mode so it is better to keep it one. I will try it.