I've had good flatness and durability with the thin China diamond plates with rounded corners. My DMD 400 diamond plate still has even diamonds and good cutting power after 20 years; used on hard stones (ceramics, Arks) and cheap kitchen knives. Can u find this?

3x10", 400/1200 grit, ~27$, 2 year warranty. https://smile.amazon.com/DMD-Double-Sided.../dp/B088YMXTPT DMD Double-Sided Diamond Sharpening Stone

Chisel in jig on cheap diamond plates. https://youtu.be/f4BEQeW8cdo Stop Sharpening with Sandpaper! -Rex Krueger. You can ditch the sandpaper and get sharp with affordable diamond stones.

My DMD 400 diamond plate has lasted 20 years; sharpening and flattening hard stones; still flat; no balding.

3x10", 400/1200 grit, 26$, 2 year warranty. https://smile.amazon.com/DMD-Double-Sided.../dp/B088YMXTPT DMD Double-Sided Diamond Sharpening Stone

Ultra Sharp are reputable with lifetime warranty. 10% off: https://www.bestsharpeningstones.com/category\_details.php?category\_id=62

S110v Spyderco, DMT fine 600 grit diamond plate, 3 and 1 micron diamond paste strops. https://youtu.be/3KYjmUyCmIw?t=330 Knife Sharpening | Simplest Way To Hair Whittling Sharp | Entire process Shown. OUTDOORS55