I am not sure if I should configure the logger to filter these out, or if I can disable the “TransformStep”? I don’t get any value out of these messages.
Unfortunately the Gradle logger is not really configurable fine-grained, you can just use -i and -q.
And as those are info-level logs, if you use -i, you get those log lines.
I doubt there is much you can do about that, except not using -i or capturing the output and filtering it instead of plainly forwarding it.
The latter definitely works, as I do that for testing that my plugin is properly emitting TeamCity service messages without them actually appearing in the build output as there they should not affect the current TeamCity build.