RE: the Konrad cap problem: easily solved with a Dremel (or, less easily, a small round file). The pen cap twists off easily, and the acrylic cap is easily translucent with a strong light so you can see what part of the cap the nib is touching. There is an inner cap (also easily removed).
It can be tricky to figure out exactly what material you need to remove, so there is some planning involved. But in the end it's easily fixed.
Edited by Dr.X, 18 August 2019 - 04:00.