Magpul released their low-profile covers for M-LOK rails. Each is 9.5 inches long, covering 6 M-LOK slots. It can be cut as needed. Color comes in black or Flat Dark Earth. Price is $15.95
https://www.magpul.com/products/m-lok-rail-cover-type-1
Enhanced AR magazine release is an aluminum piece that can be added to increase touch surface area. Price: $19.95
https://www.magpul.com/products/magpul-enhanced-ar-magazine-release
From: Magpul