Now that Mullvad is introducing new features like:
I would like to see these integrated into GLiNET routers in the GUI. More specifically, is there any plan for the Shadowsocks integration ? If so, what is an approximate timeline for the integration ?
These updates are for the Mullvad Client APP, not WireGuard/OpenVPN client which GL firmware supported.
Perhaps they are not suitable for GL firmware.
Though i'd still agree with op (asside from client options).
According mullvads blog post:
Although there might be a other article i readed this from, but mullvad wants you to use 10.64.0.1 as dns, but the scripts still generate config with this hardcoded external dns.
Since ip addresses can change ownership overtime (it is still working), its maybe not so safe to assume it always stays mullvad.
I understand. Thanks for the clarification.
It would be great though to have it baked into GL routers, or be handled separately through the mullvad client (just like tailscale for example). The first linked article for Shadowsocks is of paramount importance for my case, and I assume it's for others as well.
Mullvad does not provide OpenWrt packages so far 
Well, there are arm64 builds at least. That will be a good start.