1. I've used the override for local target platform site to test contents of a TP was building, so that's still a valid use case.

2. I don't use the local composite but I believe others have, particularly devs whose fixes span multiple projects (eg., Central/Server/Base).

3. `-Presults -Dfetch-zip-for-aggregate.skip` is only for the JBT agg, not the other aggregates. Only that build produces the results (build metadata) and pulls down the other zips. We've talked about replacing that with a mojo, but until we have something else it should stay. 

If you want to apply your current PR, I can fix the doc after that so we continue to list the viable commandline options and where they're useful.