This release includes feature improvements (including motor brake support) and bug fixes. It also introduces support for the forthcoming EXP1HCL closed loop board. For upgrade notes and details of the changes, see https://github.com/Duet3D/RepRapFirmware/wiki/Changelog-RRF-3.x-Beta-&-RC#reprapfirmware-340beta3.
Users running with attached SBC should upgrade to this release from the unstable feed of the package server. Users running in standalone mode, use the files here.