Nat's analysis is right on. Proxies might pep up editing but likely not affect export, as the original large files would be in play.
If you must have 4K, try this...
Install version 8.45. Ignore any virus prompts.
1. Open a new VP project and add your 'candles' file to the sequence.
2. Right-click | COPY the clip.
3. Press <ctrl-v> to repeatedly paste the clip to the sequence nine times.
4. Export Sequence 2 by clicking the LOSSLESS button on the toolbar.
5. Close VP. Launch your original project, lock all but the 'candles' track, replace its content with the lossless clip, trim as necessary and add fades. Unlock all tracks.
Export as AVI format, using the MPEG4 compressor at 15fps.
Another approach, not tested here, would be to export without overlays. You might even export this intermediate step at 1080. Then bring the export into a new project as a clip and add the clock, snow and text. Create the final export at 4K if desired.