I have discovered a Telegram channel that regularly publishes OpenWrt firmware from the master tree. The channel is called “mwan3” and can be found at the following link: Telegram: Contact @mwan3
The channel is run by a user named “mwan” who is a developer for OpenWrt. The firmware that is published on the channel is built using the latest code from the master tree and is therefore considered to be unstable. However, it can be useful for testing new features or for users who want to run the latest version of OpenWrt.
Plus, if you want recent snapshot builds, the OpenWrt project itself offers them on our download servers – there is no need for 3rd-party builds: Index of /snapshots/targets/mediatek/filogic/