Many thanks for the reply. Yes, I found OpenWisp but it looks a little heavy and I understand why given its heritage and aspirations for national scale. It's also quite complex.
I was hoping for something a bit lighter, dashboard-type approach detailed config can be done in the individual units but today we have to login to each one separately to see what it's doing.
I've built a CLI tool called OpenWrt Configurator, which can manage and provision multiple devices using a CLI + JSON config file. WebUI is in the works.