As it happened, Attended Sysupgrade with the latest version of OpenWrt 25.12, since it became the default approach to update OpenWrt devices, started seeing a spike in popularity.
When I first tried this, I was either 1st in the queue or just a few users behind. Days later, when the next version (25.12.1) was released, this jumped to around 200-300. Now, with another release (25.12.2), the servers cannot handle it anymore.
Server response: server overload, queue contains too many build requests: 1001
Following a discussion with one of my visitors, it was suggested that I use someone else’s server for Attended Sysupgrade, but there is always a catch to that. The recommended server uses SNAPSHOT builds as default, which I do not recommend for a production or business environment. While you can play with it on a home router, in business, you need to rely on stability.
I have been thinking that maybe I will create my own server for that purpose. I already have a small mini-PC at home (and at work) — a Chromebox repurposed as an Ubuntu Server running Docker. My usage is not massive, and there is plenty of computing power available.