Yeah you’re basically just running a script block and manually pulling what you want.
The PackageManagementResource actually contains the Nuget package. It’s simply not meant for DSC, it’s meant for PowerShell … not all modules are DSC modules, after all.
DSC only really has a mechanism for pushing DSCResources, not “all” resources. If you’re asking about a module in order to pull non-DSC resources into the mix (like chocolatey) you can always author a module for that. Heck in the script block you already started the code. But be aware it CAN’T be used for downloading DSC Resources (I might have been confusing your intent earlier in thinking you were trying to download DSC modules via the PSGallery … that won’t work).