How to get for each non blank data entry in a range output in three columns containing the entry itself , the column header and the row header

I start with a range of data (a formula for instance combining the column/row header and/or "text" and or empty items).
the first row above the range is a column header (number or letter or empty). the first column left of data is a row header (descending numbers or letter or empty). All data, column/row headers are unique no repetitions (except the blanks).

As output I would like to get 3 columns 1 | 2 | 3 data | col header | row header

this data being only non blank entries (example of formula if(TRUE/FALSE,B1&A3,""). I add this because it seems that the formula output cannot be referenced always ? if B1&A3 as data entry then it should take it in the list if "" then it should evaluate the cell as blank and omit from the list.

1. I made a helper column containing all data
2. tried to used a Filter() to remove the blank entries in the column. resulted in a #SPILL
3. Tried to get the header column and succeeded with CONCAT(REPT function
4. tried to get the row header but did not succeed with INDEX MATCH

A particular solution, using TOCOLs ignore parameter:

1 - Ignore blanks
2 - Ignore errors

=LET(
    data, B2:E7,
    col_header, A1:E1,
    row_header, A1:A7,
    result, VSTACK(
        {"Label", "Col", "Row"},
        HSTACK(
            TOCOL(data, 1, TRUE),
            TOCOL(IF(ISBLANK(data), NA(), INDEX(col_header, 1, COLUMN(data))), 2, TRUE),
            TOCOL(IF(ISBLANK(data), NA(), INDEX(row_header, ROW(data), 1)), 2, TRUE)
        )
    ),
    result
)