Module with Add-WindowsCapability proxy function to which allows bypassing WSUS for Add-WindowsCapability.

Add-WindowsCapability.ps1

# iex ((New-Object System.Net.WebClient).DownloadString('https://gist.githubusercontent.com/realslacker/fc8784324eea99e7aea48e54d8847704/raw'))
#Requires -Modules DISM

function Add-WindowsCapability {

    [CmdletBinding()]
    param(
        [Parameter(ParameterSetName='Online', ValueFromPipelineByPropertyName=$true)]
        [Parameter(ParameterSetName='Offline', ValueFromPipelineByPropertyName=$true)]
        [ValidateNotNullOrEmpty()]
        [string]
        ${Name},

        [Parameter(ParameterSetName='Online', ValueFromPipelineByPropertyName=$true)]
        [Parameter(ParameterSetName='Offline', ValueFromPipelineByPropertyName=$true)]
        [ValidateNotNullOrEmpty()]
        [string]
        ${Recipe},

        [Parameter(ValueFromPipelineByPropertyName=$true)]
        [switch]
        ${LimitAccess},

        [Parameter(ValueFromPipelineByPropertyName=$true)]
        [ValidateNotNullOrEmpty()]
        [string[]]
        ${Source},

        [Parameter(ParameterSetName='Offline', Mandatory=$true, ValueFromPipelineByPropertyName=$true)]
        [string]
        ${Path},

        [Parameter(ParameterSetName='Online', Mandatory=$true, ValueFromPipelineByPropertyName=$true)]
        [switch]
        ${Online},

        [Parameter(ValueFromPipelineByPropertyName=$true)]
        [string]
        ${WindowsDirectory},

        [Parameter(ValueFromPipelineByPropertyName=$true)]
        [string]
        ${SystemDrive},

        [Parameter(ValueFromPipelineByPropertyName=$true)]
        [Alias('LP')]
        [string]
        ${LogPath},

        [Parameter(ValueFromPipelineByPropertyName=$true)]
        [string]
        ${ScratchDirectory},

        [Parameter(ValueFromPipelineByPropertyName=$true)]
        [Alias('LL')]
        [Microsoft.Dism.Commands.LogLevel]
        ${LogLevel},

        [Parameter(ParameterSetName='Online')]
        [switch]
        ${BypassWsus}

    )

    begin {

        $BypassWsus = $PSBoundParameters.Keys -contains 'BypassWsus'
        $PSBoundParameters.Remove( 'BypassWsus' ) > $null

        if ( $BypassWsus ) {

            # get the current WSUS setting
            $UseWUServerValue = Get-ItemProperty -Path HKLM:\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU -Name UseWUServer -ErrorAction SilentlyContinue |
                Select-Object -ExpandProperty UseWUServer

            # get current servicing settings
            $LocalSourcePath = Get-ItemProperty -Path HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Servicing -Name LocalSourcePath -ErrorAction SilentlyContinue |
                Select-Object -ExpandProperty LocalSourcePath
            $RepairContentServerSource = Get-ItemProperty -Path HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Servicing -Name RepairContentServerSource -ErrorAction SilentlyContinue |
                Select-Object -ExpandProperty RepairContentServerSource
        
            # if WSUS is turned on we turn it off temporarily
            if ( $UseWUServerValue -eq 1 ) {

                Write-Verbose 'WSUS is enabled, bypassing for installation...'
    
                Set-ItemProperty -Path HKLM:\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU -Name UseWUServer -Value 0

                if ( $LocalSourcePath -eq $null ) {

                    New-Item -Path HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Servicing -Force -ErrorAction SilentlyContinue > $null
                    New-ItemProperty -Path HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Servicing -Name LocalSourcePath -Value '' -Force > $null

                    $RemoveLocalSourcePathProperty = $true

                } elseif ( $LocalSourcePath -ne '' ) {
        
                    Set-ItemProperty -Path HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Servicing -Name LocalSourcePath -Value '' -Force > $null

                    $ResetLocalSourcePathProperty = $true

                }

                if ( $RepairContentServerSource -eq $null ) {

                    New-Item -Path HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Servicing -Force -ErrorAction SilentlyContinue > $null
                    New-ItemProperty -Path HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Servicing -Name RepairContentServerSource -Value 2 -PropertyType Dword -Force > $null

                    $RemoveRepairContentServerSource = $true

                } elseif ( $RepairContentServerSource -ne 2 ) {
        
                    Set-ItemProperty -Path HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Servicing -Name RepairContentServerSource -Value 2 -Force > $null

                    $ResetRepairContentServerSource = $true

                }

            }

        }

        try {
    
            $outBuffer = $null
        
            if ( $PSBoundParameters.TryGetValue( 'OutBuffer', [ref]$outBuffer ) ) {

                $PSBoundParameters['OutBuffer'] = 1
        
            }
        
            $wrappedCmd = $ExecutionContext.InvokeCommand.GetCommand( 'Dism\Add-WindowsCapability', [System.Management.Automation.CommandTypes]::Cmdlet )
        
            $scriptCmd = { & $wrappedCmd @PSBoundParameters }
        
            $steppablePipeline = $scriptCmd.GetSteppablePipeline( $myInvocation.CommandOrigin )
        
            $steppablePipeline.Begin( $PSCmdlet )
    
        } catch { throw }
    }

    process {
    
        try {

            $steppablePipeline.Process( $_ )
    
        } catch { throw }

    }

    end {
    
        try {

            $steppablePipeline.End()
    
        } catch { throw }

        # turn back on WSUS if applicable
        if ( $BypassWsus -and $UseWUServerValue -eq 1 ) {

            Write-Verbose 'Resetting WSUS settings...'

            Set-ItemProperty -Path HKLM:\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU -Name UseWUServer -Value 1

            if ( $RemoveLocalSourcePathProperty ) {

                Remove-ItemProperty -Path HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Servicing -Name LocalSourcePath -Force -Confirm:$false -ErrorAction SilentlyContinue

            }

            if ( $ResetLocalSourcePathProperty ) {

                Set-ItemProperty -Path HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Servicing -Name LocalSourcePath -Value $LocalSourcePath

            }

            if ( $RemoveRepairContentServerSource ) {

                Remove-ItemProperty -Path HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Servicing -Name RepairContentServerSource -Force -Confirm:$false -ErrorAction SilentlyContinue

            }

            if ( $ResetRepairContentServerSource ) {

                Set-ItemProperty -Path HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Servicing -Name RepairContentServerSource -Value $RepairContentServerSource

            }

        }

    }

    <#

    .ForwardHelpTargetName Dism\Add-WindowsCapability
    .ForwardHelpCategory Cmdlet

    #>

}