In the mean time, I have downloaded your dataset and loaded it in a PRT Loader.
Since the PTS file does not tell us in advance how many points it contains, loading it always defaults to Every Nth Point, so the whole file has to be read and points skipped according to the Viewport % value.
For that reason, I highly recommend converting the PTS file to PRT first (as shown in the video).
Your PTS file contains Position, Intensity and Color just like the example I showed in the YT video.
In the latest version of Krakatoa, you can simply select the PRT Loader, and in the Krakatoa Render dialog, under the Save Particles rollout, click the >> button between the two channels lists. Select “SET Channels List From Selected PRT Objects” and the right list will be set to Position, Intensity, Color automatically!
Then just save to a new PRT file name.
Remove the PTS from the PRT Loader, and pick the newly saved PRT file. Now you can immediately see that it contains 36,146,772 points, and you can load First N or Every Nth in the viewport for quick previews. While loading 100% is possible, it is rather slow, but 10% with Every Nth is pretty good for interacting with the scene in the viewports.
I then enabled Use Emission and set a Global Channel Override to copy Color into Emission.
The pure render time from PCache for the 36M points was 5 seconds on my laptop, 13.7 seconds including the PRT file loading.