@@BlankFirstPage Gotcha. Yeah, mine was kind of tight right out of the box. I finally gave in and took it apart. The piston was bone dry. It went well. I just put some synthetic grease in between my fingers and rubbed them together some, then rubbed the parts. I didn’t use the stuff they include. It seems a bit thin to me. But it operates way better now. It’s not bad to do. 👍🏽
The bulb syringe is great, same with a blunt tip syringe -though mine is cheap plastic from Amazon vs an antique glass one passed down from a grandfather. I had never considered water temperature to be an issue, but if it's too hot it melts away the lubricants from the piston / converter. I also use Q-tips for getting up in the hard to reach places. I also syringe fill my TWSBI 580, for the reasons you mentioned, as well as to keep the ink bottle from getting any contaminants from the pen.
I also have a blunt tip cheapo plastic syringe, and I probably use that more than the glass one, because it’s easier to clean! Q-tips are a good idea, never used them to clean a fountain pen. I would worry that some of the fluff ends up in the pen but maybe that’s overthinking it?