[OpenWrt Wiki] Development builds / snapshots
https://openwrt.org/releases/snapshot12.04.2021 · Just automatic builds of the most recent source code and packages. Although snapshots are usually ok, they may sometimes contain serious bugs that prevent booting the device correctly or even prevent easy sysupgrading to new versions. snapshots are built daily, and that sets time limits to installing new packages with opkg.
[OpenWrt Wiki] Techdata: GL.iNet GL-MT1300
openwrt.org › toh › hwdataTechdata: GL.iNet GL-MT1300 The development branch can contain experimental code that is under active development and should not be used for production environments. Snapshot images may support additional hardware; however, it is experimental, considered unstable, and sometimes won't compile.