I lost the valve ball while cleaning my Bincoo immersion dripper and bought five 14 mm spares. My receipt records the size; I didn’t report a sealing test.
I poured 200 g of water through nine drippers without coffee grounds; drain times ranged from 14 to 100 seconds, but I wouldn’t overthink a daily choice.
I tried Wave and cone papers in my ORIGAMI for three months. Rinsing Kalita papers with 200 g of hot water, then hand-grinding, helped clear their papery smell.
I brewed two coffees with the SOLO and HARIO V60. I couldn’t distinguish them in one blind tasting, while another showed how much the filter choice mattered.