I would like to host non-http services and provision my own certificates with a shared IPv4 address (on port 443 though others probably need more flexibility here). This currently requires a dedicated IPv4 address due to lack of SNI routing support.
Here is an example of how to do it in go.
Note that I could share a dedicated IPv4 address among apps by running my own SNI proxy but it would be nice if the platform natively supported it.
We probably won’t build this, just because it’s relatively niche. Not because it’s not a good idea. 
Are you mostly concerned with saving money on IPs here? I think an app to do your own SNI routing is the way to go.
Yeah it mostly boils down to saving money on public IPv4 IPs while terminating TLS at the app instead of the ingress. It is my preferred approach in Kubernetes.
It’d be good to update the documentation that this doesn’t work as I expected it would and wasted some time before coughing up for a dedicated address.