LuCi: How to collect more data on autorefresh?

LuCi polls for data every 5 seconds (Autorefresh) using some sort of post request, with only "status: 1" as data.
I can see lots of great JSON data is returned which enables the page to be populated with fresh data.

I would like the page to request some extra fields, which I will make available through ubus from another piece of SW running on the device. I am struggling to learn how this mechanism works and which file to edit to be able to refresh my custom data along with the rest.

I followed this post from @jow , Redesigning LuCI (OpenWrt)?:, which was nice and detailed but it's either not clicking with me or the autorefresh mechanism doesn't follow the same route.

Is anyone able to shed some more light on this for me?
Thanks

Looks like the answer was right in front of my eyes.

For others in a similar position;
The file that deals with the Overview page, which is the one I was referring to in my post is:
/usr/lib/lua/luci/view/admin_status/index.htm (On live target)

This file has XHR.poll(...) which polls for data every 5 seconds, but this request seems to end up running the lua code above in this same file:

if luci.http.formvalue("status") == "1" then
		local ntm = require "luci.model.network".init()
		local wan = ntm:get_wannet()
		local wan6 = ntm:get_wan6net()

		local conn_count = tonumber(
			fs.readfile("/proc/sys/net/netfilter/nf_conntrack_count") or "") or 0

		local conn_max = tonumber(luci.sys.exec(
			"sysctl -n -e net.nf_conntrack_max net.ipv4.netfilter.ip_conntrack_max"
		):match("%d+")) or 4096

		local rv = {
			uptime     = sysinfo.uptime or 0,
			localtime  = os.date(),
			loadavg    = sysinfo.load or { 0, 0, 0 },
			memory     = meminfo,
			swap       = swapinfo,
			connmax    = conn_max,
			conncount  = conn_count,
			wifinets   = stat.wifi_networks()
		}

		if wan then
			local dev = wan:get_interface()
			local link = dev and ipc.link(dev:name())
			rv.wan = {
				ipaddr  = wan:ipaddr(),
				gwaddr  = wan:gwaddr(),
				netmask = wan:netmask(),
				dns     = wan:dnsaddrs(),
				expires = wan:expires(),
				uptime  = wan:uptime(),
				proto   = wan:proto(),
				i18n    = wan:get_i18n(),
				ifname  = wan:ifname(),
				link    = wan:adminlink(),
				mac     = dev and dev:mac(),
				type    = dev and dev:type(),
				name    = dev and dev:get_i18n(),
				ether   = link and link.type == 1
			}
		end

		if wan6 then
			local dev = wan6:get_interface()
			local link = dev and ipc.link(dev:name())
			rv.wan6 = {
				ip6addr   = wan6:ip6addr(),
				gw6addr   = wan6:gw6addr(),
				dns       = wan6:dns6addrs(),
				ip6prefix = wan6:ip6prefix(),
				uptime    = wan6:uptime(),
				proto     = wan6:proto(),
				i18n      = wan6:get_i18n(),
				ifname    = wan6:ifname(),
				link      = wan6:adminlink(),
				mac       = dev and dev:mac(),
				type      = dev and dev:type(),
				name      = dev and dev:get_i18n(),
				ether     = link and link.type == 1
			}
		end

		if has_dsl then
			local dsl_stat = luci.sys.exec("/etc/init.d/dsl_control lucistat")
			local dsl_func = loadstring(dsl_stat)
			if dsl_func then
				rv.dsl = dsl_func()
			end
		end


		luci.http.prepare_content("application/json")
		luci.http.write_json(rv)

		return
	end

So to add data to be returned just add another line:
rv.my_var = something
Use lua to actually get the data through ubus or reading a file etc...