Be advised, that the RUT955 is supported by "official" openwrt. Which allows complete custom setup, which I did for a large, commercial IoT project in the USA, having more than hundred devices installed, currently:
MQTT from RUT955 to AWS IoT, auto-failover between wan, wwan, wifiwan. Data queing in case of no internet. Remote config of both the RUT and low level sensors. VPN via wireguard. Low level sensors/switches connected via ModBus/RTU. Of course, writing/reading blocks of registers. Remote firmware updates. Pre-processing of sensor info, i.e. Modbus-polling and only mqttt msg in case of signal change; custom GUI (PHP) for some local config changes ...
Reasons to do own stuff: Higher availability and privacy, because indepence of RMS; newer kernels and packages; vendor-independence regarding hw; complete freedom of software customization; wide community support, because completely open source.