If you want to tailor this environment further, let me know:

Using FFmpeg as your primary tool meets the "min install" requirement perfectly. The entire installation consumes less than 30MB of disk space and takes under two minutes to set up. Once installed, the conversion process itself aligns with the "020023" time expectation: simple subtitle muxing completes in seconds, while full video re-encoding with hardcoded subtitles typically finishes within 20 minutes on modern hardware.

Software needed: None