Stop putting System. at the beginning of type tab completion!

profile.ps1

function TabExpansion2
{
    <# Options include:
         RelativeFilePaths - [bool]
             Always resolve file paths using Resolve-Path -Relative.
             The default is to use some heuristics to guess if relative or absolute is better.

       To customize your own custom options, pass a hashtable to CompleteInput, e.g.
             return [System.Management.Automation.CommandCompletion]::CompleteInput($inputScript, $cursorColumn,
                 @{ RelativeFilePaths=$false } 
    #>

    [CmdletBinding(DefaultParameterSetName = 'ScriptInputSet')]
    Param(
        [Parameter(ParameterSetName = 'ScriptInputSet', Mandatory = $true, Position = 0)]
        [string] $inputScript,
    
        [Parameter(ParameterSetName = 'ScriptInputSet', Mandatory = $true, Position = 1)]
        [int] $cursorColumn,

        [Parameter(ParameterSetName = 'AstInputSet', Mandatory = $true, Position = 0)]
        [System.Management.Automation.Language.Ast] $ast,

        [Parameter(ParameterSetName = 'AstInputSet', Mandatory = $true, Position = 1)]
        [System.Management.Automation.Language.Token[]] $tokens,

        [Parameter(ParameterSetName = 'AstInputSet', Mandatory = $true, Position = 2)]
        [System.Management.Automation.Language.IScriptPosition] $positionOfCursor,
    
        [Parameter(ParameterSetName = 'ScriptInputSet', Position = 2)]
        [Parameter(ParameterSetName = 'AstInputSet', Position = 3)]
        [Hashtable] $options = $null
    )

    End
    {
        function StripSystem([Management.Automation.CommandCompletion] $Completion)
        {
            if ($null -eq $Completion -or $null -eq $Completion.CompletionMatches) { return }

            $completionMatches = @($Completion.CompletionMatches)
            $Completion.CompletionMatches.Clear()

            foreach ($match in $completionMatches)
            {
                $newMatch = $match
                if ($match.ResultType -eq [Management.Automation.CompletionResultType]::Type)
                {
                    $newMatch = [Management.Automation.CompletionResult]::new(($match.CompletionText -replace '^System\.'),
                                                                              $match.ListItemText,
                                                                              $match.ResultType,
                                                                              $match.Tooltip)
                }

                $null = $Completion.CompletionMatches.Add($newMatch)
            }
        }

        if ($psCmdlet.ParameterSetName -eq 'ScriptInputSet')
        {
            $completion = [System.Management.Automation.CommandCompletion]::CompleteInput(
                <#inputScript#>  $inputScript,
                <#cursorColumn#> $cursorColumn,
                <#options#>      $options)

            StripSystem $completion
            return $completion
        }
        else
        {
            $completion = [System.Management.Automation.CommandCompletion]::CompleteInput(
                <#ast#>              $ast,
                <#tokens#>           $tokens,
                <#positionOfCursor#> $positionOfCursor,
                <#options#>          $options)

            StripSystem $completion
            return $completion
        }
    }
}