SharePoint 2019 (and 2016) DenyAddAndCustomizePages

In SharePoint Online we are quite used to the fact that custom scripts are denied by default in SharePoint. You can allow custom scripts by using PowerShell (https://docs.microsoft.com/en-us/sharepoint/allow-or-prevent-custom-script). Usually you realize this when you run into permission issues, missing libraries or features or migration errors. It looks like Microsoft has added this same feature to

Update Word document to a new document template by using PowerShell

Organisations usually have tons of Word documents made by using a template. If this template is later changed, you need to update all existing documents somehow. I faced this issue when migrating from SharePoint onprem to SharePoint Online, and the document template was using SharePoint Column data in document headers. All the document headers were