The grand design is the following:
Don't use the config.
Run the service programatically.
Here's an example of adding endpoints programtically: Programmatic_Endpoint_Configuration
And this, for comparison: Self-hosting_and_base_addresses
You should be able to fix this by replacing localhost
with a wildcard:
<baseAddresses><add baseAddress="net.tcp://*:1234/My/Service" /></baseAddresses>
Another option other than wildcard is to use the machine's DNS-resolvable hostname instad of localhost.