To try it out simply tick "Enable experimental 3008x and 2560x modes" in the settings tab:

After selecting this option you may observe a quick monitor blink as DisplayLink Manager restarts itself for this change to take effect.

With this feature enabled you should now be able to select 3008x1692 and 2560x1440 HiDPI modes in Displays Preferences:

Limitations of this feature

This feature is available only on Apple Silicon machines. To use new modes a display capable of displaying 3008x1692 or 2560x1440 resolution is required.
Enabling this feature will cause other resolutions to disappear, even the native ones like 4K resolution on a 4K display.

A good example of this behaviour can be seen on below screenshot, where 3008x1692 and 2560x1440 HiDPI resolutions appear on the list, but 3840x2160 is not available:

When the option is disabled, you will see that an offered list of modes is restored to original state.