Custom Asset Source Types - not possible I would love to extend Craft with a custom AssetSourceType. However it looks like components of type 'assetSource' are not extensible (enableForPlugins = false).

Is there a way to do this?
Or can I simply swap core services in the common.php without hacking the core?

My goal is to provide a 'S3CompatAssetSourceType' - the main difference to the S3AssetSourceType is the API endpoint.

Thanks.
Custom Asset sources are not possible in Craft 2 without some core hacking.

However totally doable in Craft 3 (even in the dev preview).  There is an example of how to pull it off here.