PQ - Return header(s) of column(s) for maximum average

Morning	Afternoon	Evening		Avg	Header
9	4	2		8.75	Morning
8	1	3
10	2	1
8	1	1

Morning	Afternoon	Evening		Avg	Header
9	4	8		8.75	Morning | Evening
8	1	8
10	2	11
8	1	8

Code:

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let
    Source = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
    UNP = Table.UnpivotOtherColumns(Source, {}, "Header", "Value"),
    GroupAvg = Table.Group(UNP, {"Header"}, {{"Avg", each List.Average([Value]), type number}}),
    SortDsc = Table.Sort(GroupAvg,{{"Avg", Order.Descending}}),
    Group = Table.Group(SortDsc, {"Avg"}, {{"Count", each _, type table}}),
    List = Table.AddColumn(Group, "Header", each [Count][Header]),
    Extract = Table.TransformColumns(List, {"Header", each Text.Combine(List.Transform(_, Text.From), " | "), type text}),
    Max = List.Max(Extract[Avg]),
    FilterMax = Table.SelectRows(Extract, each [Avg] = Max)
in
    FilterMax

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tolerates duplicates, extra columns and rows