I don’t have one myself, but several of the guys on YouTube use them. See “The Home Automation Guy” or “Smart Home Solver“. I can’t remember the brand they use.

If you’re not using a VPN, it’s possible your ISP is throttling your connection when it sees p2p traffic. Just another thing to look into.

Have you considered other approaches, such as Tailscale or Cloudflare Tunnels? I think you’re complicating things.

I have some SmartThings plugs that work similarly, I think they have a UK version.

TubeArchivist sounds like a better fit for that.