Hi,
I just wanted to share some news regarding the snapshot build procedure. Our buildbots now produce persistent kmod repositories for snapshots and inject them into the image, which means that it will be possible to install kmods indefinitely, even if newer builds have already been produced in the meanwhile.
This applies to all snapshots built from today on. You can check if your snapshot uses a persistent repository by inspecting /etc/opkg/distfeeds.conf and looking for an openwrt_kmods entry in the form src/gz openwrt_kmods http://downloads.openwrt.org/snapshots/targets/x86/64/kmods/4.14.37-1-7125f96094e156a5f3cc5ea14ff97fc0.
The usual caveats of snapshot builds still apply though, the builds are untested, user space packages might become incompatible over time or packages with tight kernel coupling (e.g. openvswitch + kmod-openvswitch) might still break after a while.