I’ve used Group Policy Preferences since it had been Policy Maker. I’ve always used it through the GUI but a couple of months ago I thought: Why don’t we use PowerShell for this?
Apparently, the answer is “because there is no cmdlets available”. Yes, there is Group Policy Automation Engine, but it is a paid close-source product. The built-in GroupPolicy module just does not have cmdlets for GP Preferences (only one section is covered by it – Registry).

All that lead me to starting an open-source project to PowerShellize GPP: https://github.com/exchange12rocks/PSGPPreferences
The module is at a beginning stage, but you can already install it through the Gallery: https://www.powershellgallery.com/packages/PSGPPreferences/

Currently the module allows you only to create / delete / manage groups (not even users), but I hope to add other sections relatively fast, since the foundation has been implemented.
Right now the most difficult, but crucial task is writing tests – w/o tests regressions are quite likely. That’s why it is next in the roadmap.