I think on a relative basis there's no negative tradeoffs, at least not major ones. At the end of the day its still asymmetric cryptography and relays are commodity webservers.

The keys on either side are distinct from social nostr keys, so you could simply not publish your Pub or Wallet keys to the social graph if you wanted to use it in the dark.

We're also running a completely unmodified version of strfry, so anyone looking to shield their metadata could do the same with pretty much any webhost. Relays themselves are trust-less too because of the nip44 encryption and nostr signatures. It's an improvement over most alternatives like ngrok.

The fact that nostr is web-tech and uses SSL also helps it hide in plain sight on locked down networks like public WiFi.

Lastly, because its just 2 nostr keys exchanging encrypted messages amongst other nostr traffic, it's also not obvious that it's Lightning node comms. Since anything could go over nostr, unlike proprietary stuff like LNC.