Yoe distro uses opkg package manager unlike rpm as used by poky, There is a recent patch on OE-Core mailing list on enabling zstd in opkg. Once this patch lands in OE-Core we will enable zstd in Yoe as well. in site.conf
OPKGBUILDCMD = 'opkg-build -Z zstd -a "${XZ_DEFAULTS}"'
This should improve speeds for builds. Especially final image builds which is constructed out of generated ipks.