Having just switched to the Duet WiFi, I started experimenting with the automatic mesh leveling. The RepRapFirmware uses the Z-sensor to build a bed height map automatically by probing the bed in a grid pattern. Ideally the sensor should be as close as possible to the nozzles. The bracket I've been using sits a few cm behind the nozzles. By reshaping the bracket I was able to move the sensor forward 10 mm and closer to being centered between the nozzle by 2 mm. This should improve compensation and it means the calibration grid (set by M557) can go back 10 mm farther. The odd shape of the new bracket makes it a little tricky to print. If you look at the example on the left, you'll see it includes a brim like disk that holds it at an odd angle during printing. This makes various overhangs printable. After it prints, peel the disc off and sand any rough edges off. I've attached a zip file with two versions of the bracket. One has recesses for M2.5 square nuts. The other is my preferred version. It has undersized holes that can be tapped for M2.5 screws and no nut is needed. I printed 0.2 mm layers with a 0.4 mm nozzle. You will want to bend the three pins for the sensor connector 30-45 degrees outward. This will make fitting the cable easier. Bend the pins one at a time to minimize stresses. The bracket sits close to the hot-ends so a high temperature material like colorFabb HT is recommended. UPDATE: I forgot to include what it looks like installed so you can see the realigned pins.