The new generation of Nero Recode (version 23.0.x for Nero 2021 Permanent license, and 23.5.x for Nero Subscription license) supports exporting to 4K resolution video. Please select 'AVC Ultra HD(4K) profile for output setting.
In this profile, you can also find 4 AVC 2K resolutions. Select 2K resolution to export AVC 2K files.