I'm guessing you didn't see https://github.com/IndySockets/Indy/pull/517 yet?
In any case, I'm also working on my own update to Indy for D12, but that update also includes bringing Indy's Package Generator up-to-date, which is why I haven't merged the above PR yet, as I want to see how the generated files compare to the PR's files.
Although, I guess at this point, I should just merge the PR and then merge in any generator diffs later...