ah that clears up a bit of confusion for me. Yeah I'd seen these. https://smile.amazon.com/Sakura-57370-10-Piece-Assorted-Metallic/dp/B001LXK5HS?th=1 . I had the impression the tips were a bit wider. Actually, i couldn't find the info on the product page. All I saw was "Line Size 1", so I assumed that meant the pens were 1 mm. And on my package of Pilot G2s it says "Fine/0.7 mm". I assume now that this is nib width, rather than line width (and the '1' on the gelly rolls refers to line width)? Is there a term to look out for on packages so you'll know which it's referring to? (for example those pilot g2s say 0.7 but it doesn't say if that's line or nib width)
Have you tried the OG Gelly Rolls? Or Walmart used to have a brand similar.