Using a Macro to format spreadsheet - warning, there's a twist number of columns varies

Change

    With Sheets("User to System Matrix").Cells(1).Resize(UBound(a, 1), UBound(a, 2))
        .CurrentRegion.ClearContents
        .Value = a
        Sheets("Verification Details").Cells(1).CurrentRegion.Rows(1).Copy .Cells(1, .Columns.Count + 1)
        With .Columns(.Columns.Count + 1).Offset(1).Resize(.Rows.Count - 1)
'            .Formula = "=iferror(vlookup(a2,'Known Users'!a:b,2,false),"""")"
            .Formula = "=if(vlookup(a2,'Known Users'!a:b,2,false)="""","""",vlookup(a2,'Known Users'!a:b,2,false))"
            .FormatConditions.Delete
            .FormatConditions.Add Type:=xlExpression, Formula1:="=" & .Cells(1).Address(0, 0) & "="""""
            .FormatConditions(1).Interior.Color = vbRed
        End With
    End With

to

    With Sheets("User to System Matrix").Cells(1).Resize(UBound(a, 1), UBound(a, 2))
        .CurrentRegion.ClearContents
        .Value = a
        With .Cells(1, 3).Resize(, UBound(a, 2) - 2)
            .Orientation = 90
            .Columns.AutoFit
        End With
        Sheets("Verification Details").Cells(1).CurrentRegion.Rows(1).Copy
        With .Cells(1, .Columns.Count + 1)
            .PasteSpecial 8
            .PasteSpecial
        End With
        With .Columns(.Columns.Count + 1).Offset(1).Resize(.Rows.Count - 1)
'            .Formula = "=iferror(vlookup(a2,'Known Users'!a:b,2,false),"""")"
            .Formula = "=if(vlookup(a2,'Known Users'!a:b,2,false)="""","""",vlookup(a2,'Known Users'!a:b,2,false))"
            .FormatConditions.Delete
            .FormatConditions.Add Type:=xlExpression, Formula1:="=" & .Cells(1).Address(0, 0) & "="""""
            .FormatConditions(1).Interior.Color = vbRed
        End With
    End With