Hi!

I got a 4x16 TB RAID-5 array for file storage, and reading 47 megapixel files from the array is fast and reliable, 600 MB/sec.
However, writing all those small .lrtpreview files all the time takes a lot of time, because of how RAID-5 is working.
I now have 750 000 preview files on the RAID array.

Would it be possible to redirect all those files to a temporary storage place on a super fast M.2 SSD, for instance?

Sorry, it's not possible, since the preview files are always inside the folder with the original images. That makes it much easier to move folder and preserve the preview files. Your approach had been implemented in a very early LRTimelapse version but had a lot of disadvantages therefor I changed it to the approach that we have now. None is perfect, but the way it's handled currently has more advantages.
I recommend have the sequences on a SSD while editing and moving them later to a NAS for storage when editing is finished.