I was not happy with the stock dualsense D-pad so set out to find a solution. I looked into a split D-pad, but found the buttons would move around in the controller shell and just didn't feel right. What I came up with is to use a stock D-pad, which has been cut into four, then fixed to a flexible 'membrane' to keep it together but have the buttons move without causing accidental inputs.

I picked up a couple of spare D-pads from AliExpress, cut them carefully using a Dremel (make sure you mark orientation as each direction is a different size), then with a dab of super glue, fix to the 3D printed flexible membrane piece. Reinstall and test.

https://www.aliexpress.com/item/1005007267174496.html