BTW
If you are going to install your router far away and rely on the LTE connection, make sure that your LTE modem will re-connect after network initiated disconnections.
There is a daemon checking the connection every 30s, but some users have had some problems with the re-connections.
Let your modem be on for some days and check syslog if your modem has been disconnected. logread | grep 'wwan\|uqmi_d'.
If you have multiple lines of searching on xxxxx then try to lock your modem to your PLMN code
uci set network.wwan.plmn=xxxxx
uci commit network