I actually started looking into this exact feature of uSync this past weekend and I admit that I'm stumped. I'm looking to get 2 different content types (*contentTypeAlias1 *and contentTypeAlias2) not to be exported by uSync. I've attempted the following setup, and I've not had any success --

"uSync": {
    "Settings": {
      "UIEnabledGroups": "Settings,Content"
    },
      "Sets": {
        "Default": {
          "Handlers": {
            "ContentHandler": {
              "Settings": {
                "IgnoreAliases": "contentTypeAlias1,contentTypeAlias2"
              }
            }
          }
        }
      }
    }

I am I misunderstanding the ContentHandler settings?

Yeah the aliases bit is generic for all handlers its not actually doctype aliases you are asking it to ignore but the content aliases (e.g the name) so for example don't import the 'about' page. with the content handler you can still ignore by path - but not by doctype. (https://docs.jumoo.co.uk/usync/reference/handlers#handler-specific-settings) - You could currently do it by extending the ContentHandler and replacing the

shouldimport

method, but it might actually be something that is quite easy to add to the core . so I have created an issue to pick this up https://github.com/KevinJump/uSync/issues/419

Wow! That's amazing! I apologize for the delayed response.