A more accurate way to time would be, once uploaded to youtube, you retime it from when the crosshair appears in the vault and stop the time when the cross hair disappears after killing glados.

Basically just subtract the starting time stamp of the run from the ending time stamp and you'll have your time to the nearest second.

There is the basic ihud layout in game which you are already aware of, but what you're thinking could be an external hud which is a separate program then added in obs for streaming/recording. The most common one that I see is "NohBoard" which can be found at https://github.com/ThoNohT/NohBoard/releases although there are most likely more alternatives out there if you don't like this one.

Hope that helps!

Would it not just be the same as the normal leaderboard? I understand that the graphics are different but isn't it still the same old steam pipe version or are there minor tweaks in the rtx version of portal?

If you find that the 90 FOV and motion blur still isn't enough to completely eliminate motion sickness, there are plenty of strategies you can implement externally to help. For instance:
- Medication
- Ginger (remedy for nausea)
- Distractions (commonly music)
- I've also heard that having a fan pointed towards your face can help although that may be up to the individual and not work for everyone.

There are many other ways but this is just to name a few. Hope this helps!