Matrix sub-total calculation?

Final PBIX File here: https://drive.google.com/file/d/12_k_tO8BdrXV73Lbho_whabGP-jOlasP/view?usp=sharing

Code to create the weighted average measure:

WAVG Measure = 

VAR DESIRED_ROWS = 
    FILTER(
        'Table',
        'Table'[Column1] > 0      &&
        'Table'[Attribute (from a PowerQuery unpivot] = "attribute1 selected"  ||
        'Table'[Attribute (from a PowerQuery unpivot] = "attribute2 selected"  ||
        'Table'[Attribute (from a PowerQuery unpivot] = "attribute3 selected"  ||
    )

RETURN
    DIVIDE(
            SUMX (
                DESIRED_ROWS,
                'Table'[Denominator Column] * 'Table'[Value]
            ),
            SUMX (
                DESIRED_ROWS,
                'Table'[Denominator Column]
            )
    )

Code to generate Matrix values from a weighted average measure:

_A = 

// Note - below one can use any of the *X DAX functions, such as SUMX, AVERAGEX, MEDIANX, STDEVX.S, etc.
       
VAR OUTPUT =     
            AVERAGEX(
                SUMMARIZE (
                        ALLSELECTED('Table'),
                        'Table'[Row Column]
                    )
                , [WAVG Measure]
            )
        
RETURN
    OUTPUT
       

Code to summarize the Matrix value [measure]

_A Summarized = 

// Choose AVERAGEX or SUMX below depending on one's needs


VAR OUTPUT_CELL = 
    AVERAGEX(
      SUMMARIZE('Table','Table'[Matrix Row Column])
        , [WAVG measure]
    )
RETURN
    OUTPUT_CELL