Simple things are the best, anyhow we are attracted from those complicated.
The world of the watchmakers is an example, is enough to see the success of super complicated mechanical watches.
Pineider has enriched the piston filler with a complication that allows to hide the blind cap in the barrel after having filled it, the Mystery Filler.
The system is made from 7 parts, of high precision, that allows to activate the piston hiding the button in a way that cannot interfere with the cap when posted
and protect the piston from spills of ink.