Yes :) The Lamy 2000's been with me after grad. Even had a pen craftsman resharpen my nib!

I use a syringe to refill cartridges from whatever bottle of ink I want to use. The cartridges can be reused many many times.

edit: lol, if I had reloaded the page before commenting, I would have seen all of these people saying the same thing!

Most pens either ship with or will work with a piston converter. You don't need to mod a pen just to use inks other than those available in compatible cartridges.

E.g.,

https://duckduckgo.com/?t=ffab&q=fountain+pen+piston+convert...

A lot of people just reuse empty cartridges a few times by refilling them with a blunt tip syringe (sold by most online pen/ink shops), using whatever ink they want.

It is far easier to get a blunt nosed syringe for $0.10 (not sharpened for medical use) and use it to quickly and cleanly refill cartridges with whatever ink you want.

As I said, the only converter of mine that seems to have a capacity problem is the Namiki, but for practical reasons I also almost always run carts in that pen anyway.

I don't need a project, and I'm not super interested in locking a pen into a single mode of operation. The beauty of most pens is that you can go with carts OR with a converter, depending on mood. (Obviously some, like Pelikans and TWSBI, are bottle-fill only, but you know that going in.)