Transpose column instead of rows in Power Query

Please paste this code into the advanced editor and follow the steps:

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("vZBPC8IwDMW/Sijsto620rEeh04dosj8c5k7bDPoQDZou+9v610YiLvkvSSQX3hlSbLaWNQ9pG2LxpCQFBtXuOSUO91T7uW42roqGF1jQ3ni/MJP81N6yHfOsYgJJ4rLSPkT6TmD5aW4Zv5UQqrw3xw69nXzQrADPNCCfSIkLLiNjIlYyQDu42ena4ug0VjdtbYbehN5RDzDg66RbBpHTOF8TVvNAJma2E8QH1f1Bg==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type text) meta [Serialized.Text = true]) in type table [CONSOLE = _t, SITE_CALL_NAME = _t, MTRB_SHORT_NAME = _t, METER_SHORT_NAME = _t, COMMODITY_ID = _t, TEST_DATE = _t, MF_COUNT = _t, MODIFIED_BY = _t, LINEARITY_DEVIATION_PERC = _t, AVG_of_DENSITY = _t, COMMENTS = _t, FLOW_MAX_PERC = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"CONSOLE", type text}, {"SITE_CALL_NAME", type text}, {"MTRB_SHORT_NAME", type text}, {"METER_SHORT_NAME", type text}, {"COMMODITY_ID", type text}, {"TEST_DATE", type date}, {"MF_COUNT", Int64.Type}, {"MODIFIED_BY", type text}, {"LINEARITY_DEVIATION_PERC", type number}, {"AVG_of_DENSITY", type number}, {"COMMENTS", type text}, {"FLOW_MAX_PERC", Int64.Type}}),
    #"Removed Columns" = Table.RemoveColumns(#"Changed Type",{"AVG_of_DENSITY", "COMMENTS"}),
    #"Grouped Rows" = Table.Group(#"Removed Columns", {"SITE_CALL_NAME", "MTRB_SHORT_NAME", "METER_SHORT_NAME", "COMMODITY_ID", "TEST_DATE", "MF_COUNT", "LINEARITY_DEVIATION_PERC"}, {{"All", each _, type table}, {"CountRows", each Table.RowCount(_), type number}}),
    AddTranspose = Table.AddColumn(#"Grouped Rows", "Custom", each Table.Transpose(Table.DemoteHeaders(Table.SelectColumns([All], {"MODIFIED_BY", "FLOW_MAX_PERC"})))),
    DynamicExpand = Table.ExpandTableColumn(AddTranspose, "Custom", List.Transform({1..List.Max(AddTranspose[CountRows])}, each "Column"&Text.From(_))),
    Cleanup = Table.RemoveColumns(DynamicExpand,{"All", "CountRows"})
in
    Cleanup