If you work in a 2K sequence, which is 2048X1152 - then when you go to export your settings, do not use a YouTube preset. Just use H.264 and tell it to match source settings. That will automatically set it up to create an H.264 file at 2K resolutions.
We do not have YouTube presets for 2K/4K yet. This should work.
Thanks for this. Will give it a go.