I finally got around to installing the KST 'Contactless' servos in my D420. I've had these servos for a while but just never got around to fitting them because the regular KSTs seemed to be performing fine. These new contactless servos as well as using hall effect sensors rather than regular 'pots' have a lot more torque than the regular KSTs. They are a bit pricey but I got a deal on them from Banggood when I did the original build review for the 420
I also fitted a HW 80A V4 ESC while I was at it, this is not really necessary to be honest, the 60A was doing perfectly ok, but i had another home in mind for the 60A. The 80A is a little heavier but that's not really a bad thing because it reduces nose weight requirement.