Rohrer & Kilnger Sketch Ink

I love the colours and the fact they’re waterproof…since I use them with watercolours for sketching. I’ve used both De Atrementis and Platinum Carbon inks before in my pens, sometimes without using them for months and have never had a problem with them clogging. An internet echo-chamber myth, perhaps? But the Sketch ink bottle says shake before using and that does make me wonder about them. Anyone have experience with using these inks over time? Thanks