Finally I found a great trading platform, which provides Universal Renko bars out of the box!
Version: 1.0.134 (Beta)
After testing the various settings, I recognized, that the real-time Advanced Renko bars are plotted incorrectly (the historical bars are plotted correctly).
In this screenshot you can see the correct plotting of the classic Renko bars. The bar low/close is formed by the bid price.
In this screenshot you can see Mean (Median) Renko bars. The real-time bar's close/high is plotted with the Extension offset above the bid price, but it should be plotted like the classic Renko bars:
Thanks for looking into it!