The block reinforcer is able to dupe blocks.

And how do you think does this help us in fixing it? You have provided us with zero actual information about how the dupe works. We do know of a dupe involving shift-clicking, so if that is what you want to report, then we can close this issue, as the bug is fixed in the next version. If that's not the dupe you mean, then you absolutely need to give us step by step instructions on how to execute it. And next time when opening an issue, include that info right away. Thanks.