T_XPatchset v2 is out for the Linux bridge, to reduce checks in the #multicast fast path, and to later propagate a safety multicast (in)active state to #switchdev/#DSA:
https://patchwork.kernel.org/project/netdevbpf/cover/[email protected]/
Includes some fixes and got some nice Linux selftests: https://patchwork.kernel.org/project/netdevbpf/patch/[email protected]/
This is also the version currently used in this OpenWrt draft PR for #realtek / #rtl83xx (v6 - v8): https://github.com/openwrt/openwrt/pull/18780