It's potentially useful for TLS over UDP, aka DTLS, which is A Thing. I've seen DTLS used for VPNs, but I think it can be used with things like SIP and WebRTC.

It's potentially useful for TLS over UDP, aka DTLS, which is A Thing. I've seen DTLS used for VPNs, but I think it can be used with things like SIP and WebRTC. I don't know if TLS heartbeats are used in any of these protocols, though.