HTTPS Load Balancing: Support multiple certificates for a single target proxy.
A single target proxy can be attached to a URL map containing multiple host rules, thereby allowing it to support multiple hostnames. However, a target HTTPS proxy currently only supports a single certificate. Therefore, supporting multiple hostnames using a single HTTPS global forwarding rule requires that each hostname be specified as a separate SAN within the certificate.
This is not ideal for a number of reasons: for example, some certificate authorities charge more for a single SAN than for a single-hostname certificate. A certificate with multiple SANs is also larger than necessary, potentially leading to a slower TLS handshake.
It would therefore be helpful if HTTPS Load Balancing supported multiple certificates for a target proxy by switching between certificates based on the SNI sent by the client.