Since file size is more important than quality in this scenario, math can provide the answer.
The edited video is 1h 30m 40s in duration, which is 5,440 seconds.
The max desired file size is 3 GB, which is 3 GB * 1000 MB * 1000 KB * 1000 B * 8 bits = 24,000,000,000 bits.
Divide bits by seconds to get data rate: 24,000,000,000 / 5,440 = 4,411,764 bits per second.
Divide that by 1,000,000 to get megabits per second, and round a little for convenience.
Total bit rate = 4.4Mbps
Audio bit rate needs to be subtracted from the total to figure out what’s left for video. The audio bit rate is 176kbps (~0.2Mbps), so that leaves 4.2Mbps for video. If the 3GB cap is a hard cutoff requirement, then round down to 4Mbps to provide a buffer for overages during encoding.
Now for the settings on the Codec tab:
- Codec: As @DRM said, HEVC (called libx265 in the Codec dropdown box) will produce a file that is about twice the quality of libx264 when constrained to the same bitrate, but libx265 will take six times longer to encode the file. Choose whichever codec fits your workflow best.
- Rate control: Average bitrate
- Bitrate: 4M
- GOP: 180 (60fps * 3)
- B frames: 8
- Codec threads: 0
- Dual pass: It can help some (not night-and-day), but it nearly doubles the export time
- On the export panel’s “Other” tab, look for a
presetline. It may be set tofastormedium. Change the line to saypreset=veryfastfor libx264 orpreset=slowfor libx265.
And most critically, do not use hardware encoding. As for parallel processing, it’s usually okay to leave on. Turn it off if unexplainable problems happen in the export, like artefacts or filters that look good in preview but not when exported.
This will be the best that can be done in 4Mbps (to fit within the 3GB cap). If it doesn’t look acceptable, then the resolution will need to be lowered, or the cap will need to be raised.
EDIT: Added recommendation for the preset option