Is Tor PluginTransport Webtunnel/Lyrebird available on OpenWrt armv7?

I'm using ea8500. Currently there is a tor package for openwrt ipq806x (armv7) but there seems to be no support for PluginTransport webtunnel, the official tor browser bundles a binary lyrebird (used to be a separate bin called webtunnel) to facilitate that however that is x86 or aarch64 only. See dist.torproject.org, there is no tor-expert-bundle or tor browser prebuilt binaries for armv7.

Any ideas how to cross compile lyrebird for ea8500 or wider armv7 routers?

Thanks.

Can you point to the source code if your wish, preferably in the form of github PR?

The main repo of lyrebird for webtunnel transport is here.

The tor browser bundle arm build progress is doc'ed here and it seems arm build will be available soon (yet).