Caching for that 1.6GB HEVC file took 18:45. Once done, the file (or fully cached project) can be reloaded in just seconds - as long as the cache hasn't been cleared.
Proxy editing would be a help here, where a smaller file is substituted for editing and the originals swapped back for export. It's common practice with many editors.
Prism can batch convert files to smaller sizes, which will load much faster in VP.
Your project might look just fine at lower resolution; no substitution necessary.
If the camera can record using H264 encoding (which may be the case with the Sony camera), that should be speedier when importing into VP.
Check the Sony's stats. One easy way to do that is to install MPC-BE, an all-purpose, free media player. Click the FILE menu, then PROPERTIES. This file..
Please leave your link up for a few days, if possible.
After your original file was converted to AVC (H264) encoding at the same resolution it loaded in less than ten seconds.