I get a similar response using my produced (.m2ts) clip AND when using PD12, so this isn't something unique to PD13 or to your source clip.
Based on what I'm seeing, this seems to be a case of asking too much to get anything close to real-time performance out of even high-end hardware, and the easiest (least frustrating) approach is probably to do one step at a time and produce afterwards.
For example, I was able to produce the clip to 32x in 32 seconds, so it took roughly half the time to produce the full clip at normal speed. I could then place that clip in the timeline and it previews exactly like you'd want it to
In other words, here's how to get through this project: Set up your speed change and produce that to a high quality output. PD13 will automatically load that clip when you reenter the editing room, then place that clip in the timeline and do the next step in your editing process, produce that, repeat. I'm guessing that not only will this one-step-at-a-time approach be quicker, it will actually be enjoyable
Ok, maybe not quite enjoyable, but certainly a vast improvement over pulling your hair out in never-ending agony. I certainly hope so!
YouTube/optodata
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