Consolidate multiple tables with comment text columns

let
    nested = Table.FromRecords(
        {[Code = 6100,
        Custom = Table.FromRecords(
            {[Desc = "Item 1", Prior = 8, Current = 9, Var = 1, Comment = "reason a"],
            [Desc = "Item 2", Prior = 5, Current = 4, Var = -1, Comment = "reason b"]}
        )],
        [Code = 6200,
        Custom = Table.FromRecords(
            {[Desc = "Item 1", Prior = 6, Current = 11, Var = 5, Comment = "reason c"],
            [Desc = "Item 2", Prior = 4, Current = 7, Var = 3, Comment = "reason d"],
            [Desc = "Item 3", Prior = 1, Current = 3, Var = 2, Comment = "reason e"]}
        )]
        }
    ),
    idx = Table.AddIndexColumn(nested, "idx", 1, 1),
    idc = Table.TransformColumns(idx, {"idx", (x) => "Comment table " & Text.From(x)}),
    comm_columns = List.Transform({1..Table.RowCount(nested)}, (x) => "Comment table " & Text.From(x)),
    xp_tbl = Table.ExpandTableColumn(idc, "Custom", {"Desc", "Prior", "Current", "Var", "Comment"}),
    group = Table.Group(
        xp_tbl,
        "Desc",
        List.Transform(
            {"Prior", "Current", "Var"},
            (x) => {x, each List.Sum(Table.Column(_, x))}
        ) & 
        {{"c", (x) => Record.FromList(x[Comment], x[idx])}}
    ),
    xp_rec = Table.ExpandRecordColumn(group, "c", comm_columns)
in
    xp_rec