Proxy servlet for sitemaps elements?

I’ve got a couple of services available on my LAN (e.g. Grafana and frontail) embed in my sitemap/HABpanel. I’d like to be able to view the data from these when outside of my LAN i.e. using myopenhab or a dynamic dns.

As I understand, openHAB would need to proxy these elements/widgets…is there an obvious way to do this that I’ve missed?