In a comment to my previous question about the transfer of speed reading skills to other languages, someone wondered whether this would be affected by the writing system. This is very plausible. In his video on learning Russian, Steve Kaufmann says that, in his own experience, (normal) reading in your "native writing system" is always easier (e.g. Czech versus Russian for a native speaker of English), so it is reasonable to assume that this also applies to speed reading (assuming the same amount of practice for Czech and Russian).
For a writing system that is very different, we can go to Chinese. I found out that Cheng & Tsui published A Course on Chinese Speed Reading by Yang Li. However, I wonder if there any online courses or online resources that teach speed reading in Chinese.