Do you fly with the pens tip up?

I bring back gel pens & refills in my carry-on, stored any which way, and they write without issue. Have you thought about a pressurized ballpoint like a Uni Tank? https://www.jetpens.com/blog/guide-t...ce-pens/pt/748

I have also resigned myself to functional "cheap and cheerful" (mostly ballpoint) pens while traveling and prefer extra fine points. JetPens offers gel pen sampler packs if you're willing to spend a bit for testing https://www.jetpens.com/Gel-Pen-Sets/ct/2676 Many of the Japanese pen manufacturers offer a nicer "office pen" which accepts their refills and there's also independent pen makers which offer pens that accept a wide variety of refills.