I should note that CPU frequency scaling works with mvebu too. Several users have compiled and run it, maybe it could save <1W power not even sure it does that without voltage scaling too. Again, there are no thermal issues with my WRT32X under reasonably heavy loads.
EDIT: Hadn't checked that thread in a while, it looks like CPU scaling was added to for mvebu (WRT routers) in November which means it should be included in OpenWrt 21.02. Looks like hynman noticed it even lowers temps by 2 degrees avg. Hopefully it doesn't add any latency like it did for the R7800 initially.