Skimming through the discord reveals that this version supposedly is properly optimized which is why they didn't ship a low spec version
I'd have to disagree with the assessment that this version is properly optimized, or at least with the notion that it makes the SD version redundant, I'd agree if they simply said that this version is better optimized than the previous HD version, that would be true, but it certainly doesn't reach the same level of performance that was achievable in the SD version
There also seems to be some kind of leak as the player interacts in a room that can only be fixed by the player leaving and entering the room they are in, emphasis on only, as saving and loading doesn't seem to fix the problem, even quitting the game before loading the game, but leaving and entering the room completely fixes this, even if nothing changed visually. With that it's not surprising that the trials is where there are the most performance problems as players can't leave and enter the trial room at will, so the performance degradation accumulates over the course of several hours until the game struggles to even reach 30 FPS even though a few hours back the game was running perfectly fine