Hi there,
From what I understand, most of the Wallpapers and Dreams shared on WinCustomize.com are created by individual users and generously uploaded for the community. It’s possible that your specific monitor resolution hasn’t received many requests yet.

You might consider sending a polite PM to the creator of the wallpaper or dream you're interested in. If enough users express interest in your resolution, they may be open to including it in future updates.
Hope that helps — and hope you get the resolution you need!
Best regards,

Basj,
Stardock Community Assistant.