controlport CLI param missing from help and causing address in use error

[rbucker]

In the multiplezone on one server doc it is suggested that it is possible to run multiple bedrock servers on the same machine.... and the CLI is provided. When I tried to run the 3 commands I got all sorts of errors which I finally identified as an address already in use localhost:9999.

I was not able to locate localhost:9999 in the help so I search the code. There is a param labeled controlport, however, [1] it's not included in the help and [b] it's not included in the doc ... and if it's supposed to autoignore it's not obvious.