There are a few places in the official MirrorMaker 2.0 docs that are either confusing or incorrect. Here are a few examples I've found:
The documentation for the 'sync.group.offsets.enabled' config states that it's enabled by default here, but the actual source code indicates that it's disabled by default here. I'm unsure if the intent is to have it enabled or disabled by default.
There are also some numerical typos, here and here. These lines state that the default is 6000 seconds (and incorrectly that it's equal to 10 minutes), but the actual default is 600 seconds, shown here and here