This is a collection of stuff that I created or found (random mac) to make my life easier using a zoo of old plastic routers to unlash the magic of a "distributed" vlan switch / router infrastructure that spans the whole house
openwrt is cool but needs some improvements and these can be very simple, pragmatic and useful.
Just get inspired by the small collection and feel free to fork it and to contribute to it. Also it might be a cool idea to generate/modify these shell scripts with ansible on a fake machine which has python which then writes the generated scripts to the routers.
Hopefully the maintainers of openwrt.org get inspired by it to improve openwrt the one or the other way.
have fun with your routers and make sure that $your_friendly_government does not hack your stuff :-)