For those testing beta 3 there are now beta3+1 builds of the main board firmwares at https://www.dropbox.com/scl/fo/bx70c7u0bshq79ez83mnn/AKMj4UCEimtQuGYxRj_d0ew?rlkey=7yiq3x5fcae3v2ogslfocx1op&dl=0. The most important bugs fixed in this version are:
Duet 2 Ethernet only: network connection was unreliable
Duet 3 6XD only: at high step rates the minimum interval between steps was not honoured, leading to steps merging
See https://github.com/Duet3D/RepRapFirmware/wiki/Changelog-RRF-3.x-Beta#reprapfirmware-360-rc1-in-preparation-changes-since-360-beta3 for other fixes and changes.