No problem at all, sounds like this spring is different from the older ones.
Just out of irresistable curiousity, I did give unscrewing it a try, and it came off easily - little 6 mm open-ended wrench on the flats, end piece in a vice, turn the wrench. There is threadlocker in there, so I cleaned everything off and then put it all back together with locktight blue (242). I'll keep a close eye on it for a while, next time I take it out, to make sure it doesn't start unscrewing itself. If that's a problem, I have two stronger flavors of locktight.
So, it does unscrew, but I can't speak to the wisdom of unscrewing it, and I see no real reason to do it again given that it's threadlocked together, and it can be cleaned as one assembly. If anyone else has any reason to want or need to do this, be cautious because 5 Nm is not much torque - basically, just enough torque to realign the flats on the rod to the flats on the end piece.