Create a merge column by comparing 3 conditions to a 2nd table (Excel IFS/INDEX(MATCH) to PQ)

I took a stab at this with the below dummy data. The approach is to merge on the columns you are interested in, then, rather than expand on the nested joins, perform a check against the merge column and perhaps pull out the related ID. When multiple rows are joined, we just take the first row and ignore any others, in line with MATCH's behavior (with 0 in last arg) in Excel.

TracerTbl

PSTable

Power query (M) in advanced editor:

let
    <...>
    #"Removed Columns1" = <...>,
    MergeOnID = Table.NestedJoin(
        #"Removed Columns1", {"UserID"}, PSTable, {"ID"}, "ID_Check", JoinKind.LeftOuter
    ),
    MergeOnEmail1 = Table.NestedJoin(
        MergeOnID, {"Email Address"}, PSTable, {"Email 1"}, "Email1_Check", JoinKind.LeftOuter
    ),
    MergeOnEmail2 = Table.NestedJoin(
        MergeOnEmail1, {"Email Address"}, PSTable, {"Email 2"}, "Email2_Check", JoinKind.LeftOuter
    ),
    //For each merged column, perform a check calculation
    MergeCheckTransforms = Table.TransformColumns(
        MergeOnEmail2,
        {
            //Gives true/false on whether TracerTbl[ID] was found in PSTable
            {"ID_Check", each not Table.IsEmpty(_), type logical},
            //If no matches found on Email1, return null, otherwise return the ID of first row matched
            {"Email1_Check", each if Table.IsEmpty(_) then null else Table.First(_)[ID], Int64.Type},
            //If no matches found on Email2, return null, otherwise return the ID of first row matched
            {"Email2_Check", each if Table.IsEmpty(_) then null else Table.First(_)[ID], Int64.Type}
        }
    ),
    //Assign validated ID based on matches, with precedent order of: ID, Email1, Email2. 
    //If no matches at all, return null
    AddValidatedId = Table.AddColumn(
        MergeCheckTransforms,
        "Validated ID",
        each
            if [ID_Check] then
                [UserID]
            else if [Email1_Check] <> null then
                [Email1_Check]
            else if [Email2_Check] <> null then
                [Email2_Check]
            else
                null,
        Int64.Type
    )
in
    AddValidatedId

Here is the output. You can remove the Check columns or perform whatever other transforms as desired.

Edit: Including screenshot of output as it's a little more readable: