Enable and/or Report on the SPWeb Property Settings Related to the HTMLDesign Feature on an SPO Site

Enable-HtmlDesignFeature.ps1

$site = "https://contoso.sharepoint.com/sites/publishing-site"

Add-Type -Path "C:\Microsoft.SharePointOnline.CSOM.16.1.6008.1200\lib\net45\Microsoft.SharePoint.Client.dll"
Add-Type -Path "C:\Microsoft.SharePointOnline.CSOM.16.1.6008.1200\lib\net45\Microsoft.SharePoint.Client.Runtime.dll"


function Get-HtmlDesignFeatureProperties
{
    [cmdletbinding()]
    param
    (
        [parameter(Mandatory=$true)][Microsoft.SharePoint.Client.ClientContext]$ClientContext
    )
   
    begin
    {
        $results = @()
    
        $propertyNames = @(
            "HtmlDesignViewNameHtmlDesignFiles",
            "HtmlDesignViewNameHtmlDesignsAndRelatedFiles",
            "HtmlDesignViewNameHtmlMasterPages",
            "HtmlDesignViewnameHtmlPageLayouts",
            "HtmlDesignViewNameDesignTemplates",
            "HtmlDesignViewNameAllDeviceChannelsSimpleListing"
        )
    }
    process
    {
        $properties = $ClientContext.Site.RootWeb.AllProperties
        $ClientContext.Load($properties)
        $ClientContext.ExecuteQuery()

        foreach( $propName in $propertyNames )
        {
            $obj = New-Object PSCustomObject -Property @{
                Site          = $ClientContext.Url
                PropertyName  = $propName
                PropertyValue = "** NOT FOUND **"
            }

            if( $properties.FieldValues.ContainsKey( $propName.ToLower() ) )
            {
                $obj.PropertyValue = $properties.FieldValues[$propName.ToLower()]
            }

            $obj | SELECT Site, PropertyName, PropertyValue
        }
    }
    end
    {
    }
}


function Enable-HtmlDesignFeature
{
    [cmdletbinding()]
    param
    (
        [parameter(Mandatory=$true)][Microsoft.SharePoint.Client.ClientContext]$ClientContext
    )

    
    begin
    {
        $publishingSiteFeatureId = "F6924D36-2FA8-4f0b-B16D-06B7250180FA"
        $htmlDesignFeatureId     = "a4c654e4-a8da-4db3-897c-a386048f7157"
    }
    process
    {

        $features = $ClientContext.Site.Features
        $ClientContext.Load($features)
        $ClientContext.ExecuteQuery()

        if( $( $features | ? { $_.DefinitionId -eq $publishingSiteFeatureId -or $_.DefinitionId -eq $htmlDesignFeatureId } ) )
        {
            $ClientContext.Site.Features.Add( $htmlDesignFeatureId, $true <# force #>, [Microsoft.SharePoint.Client.FeatureDefinitionScope]::None ) | Out-Null
            $ClientContext.ExecuteQuery()
        }
        else
        {
            Write-Warning "The 'Publishing Site' feature must be activated on '$($ClientContext.Url)' before the 'HTML Design' Feature can be forcefully enabled."   
        }
    }
    end
    {
    }
}


if( -not $credential )
{
    $credential = Get-Credential
}

$clientContext = New-Object Microsoft.SharePoint.Client.ClientContext( $site )
$clientContext.Credentials = New-Object Microsoft.SharePoint.Client.SharePointOnlineCredentials( $credential.UserName, $credential.Password )

Enable-HtmlDesignFeature -ClientContext $clientContext

Get-HtmlDesignFeatureProperties -ClientContext $clientContext