Hello. Regarding the problem with exporting videos on Linux (topic now archived) I had several occasions since then to try it. I can confirm that it works correctly, no prblems anymore.
The problem was with the acceleration of the ASUS motherboard. The BIOS has an acceleration option and it was set to high a long time ago. o each time shotcut would be exporting the fans would starting to spin much faster. Actually you could hear when the heavy processing was going during export as it happens in batches, each one having 1 or 2 seconds of silence in-between. Each segment of heavy crunching was indicated by the fans spinning much faster.
Now that the motherboard speed is back to normal, no problems at all. And actually the exports are going smoothly and faster than with the accelerated motherboard.