Preview files are not referenced when encoding.

I mainly work with Premiere 2024, but I'm having trouble with the encoding being too slow.

As for the editing, I used Robuskey to extract a person recorded against a green screen,
and then composited two still images (jpeg, png) and a video (FHD H.265 mp4 encoded with MediaEncoder).

The person's footage is a 4K/4:2:2 10bit Long-Gop/H.264 mov file.

Even though I checked "Use Preview" when exporting, it seems that the preview file is not referenced in most cases.

I tried exporting a video that was exactly 1 minute long, and the results are below.

After rendering, export directly from Premiere with "Use Preview"
  Renderer set to GPU / 1 minute 41 seconds (2025 takes 1 minute 47 seconds)
  Renderer set to software / 8 seconds (2025 takes 5 minutes 41 seconds)

After rendering, export directly from Premiere with "Don't use Preview"
  Renderer set to GPU / 1 minute 42 seconds
  Renderer set to software / 5 minutes 30 seconds

After rendering, encode with ME with "Use Preview"
  I tried all combination of Pr and ME renderer settings, and it took about 2 minutes for all four combinations

Put the rendered preview file in a sequence and export directly from Premiere
  Renderer set to GPU / 8 seconds
  Renderer set to software / 8 seconds

Whenever it takes a long time to export, it always slows down after 64% has progressed.

Is there any solution?

The PC specs are as follows.
windows11
Core i7 12700
RTX 3070
Memory 96GB
GPU drivers are up to date.