The optimization process and recommendations:

1. Avoid Subqueries (query line: 40): We advise against using subqueries as they are not optimized well by the optimizer. Therefore, it's recommended to join a newly created temporary table that holds the data, which also includes the relevant search index.
2. Explicitly ORDER BY After GROUP BY (modified query below): By default, the database sorts all 'GROUP BY col1, col2, ...' queries as if you specified 'ORDER BY col1, col2, ...' in the query as well. If a query includes a GROUP BY clause but you want to avoid the overhead of sorting the result, you can suppress sorting by specifying 'ORDER BY NULL'.

The optimized query:

SELECT
        y.id,
        y.CIDs,
        y.COLOR,
        y.XT,
        y.MP,
        y.Name,
        concat(PIDs,
        y.",",
        GROUP_CONCAT(DISTINCT y.id)) AS PIDs,
        IFNULL(y.Name,
        y.id) AS unqName 
    FROM
        (SELECT
            x.id,
            x.CIDs,
            x.COLOR,
            x.XT,
            x.MP,
            x.Name,
            concat(PIDs,
            ",",
            GROUP_CONCAT(DISTINCT x.id)) AS PIDs,
            IFNULL(x.MP,
            x.id) AS unqMP 
        FROM
            (SELECT
                m.id,
                m.CIDs,
                m.COLOR,
                m.XT,
                m.MP,
                m.Name,
                concat(PIDs,
                ",",
                GROUP_CONCAT(DISTINCT m.id)) AS PIDs,
                IFNULL(m.XT,
                m.id) AS unqXT 
            FROM
                (SELECT
                    Performance.id,
                    Performance.CIDs,
                    Performance.COLOR,
                    Performance.XT,
                    Performance.MP,
                    Performance.Name,
                    GROUP_CONCAT(DISTINCT Performance.id) AS PIDs,
                    IFNULL(Performance.COLOR,
                    Performance.id) AS unqCOLOR 
                FROM
                    Performance 
                GROUP BY
                    unqCOLOR 
                ORDER BY
                    NULL) m 
            GROUP BY
                unqXT 
            ORDER BY
                NULL) x 
            GROUP BY
                unqMP 
            ORDER BY
                NULL) y 
        GROUP BY
            unqName 
        ORDER BY
            NULL