Brilliant by Ferret

Before entry, one answer in each row must have a letter omitted, wherever it occurs, and placed in the cell at the end of its row; likewise, one answer in each column must have a letter omitted, wherever it occurs, and placed in the cell at the top of its column.
The omitted letters form a question. Having discovered the point of the extra word in ten clues (to be removed before solving), solvers must highlight the approximate answer (located in a straight line in the filled grid) to the question.

    4    Brief domestic and warn wife about casement (11, 2 words)
    12    Narrow strip of cloth and two bits of elastic on supporter (6)
    13    It’s comparatively uncommon to hold Oscar for person bawling (6)
    14    Unreserved parking allowable on excursion (8)
    15    Muslim theologian imprisoned by Mamelukes after revolution (5)
    17    Paragon Hotel – everything one holds bad (7)
    19    Sending back messenger to pursue Queen (6)
    20    Combining three species of ox, stuffing is marinated in soy sauce and grilled (8)
    21    A few rude to Wren wearing two pearl rings (8, 3 words)
    24    Soothing medical drug discovered in caper (6)
    27    Greek odes wrongly recalled besieging army (7)
    28    Nurse catches spot returning, a result of nasal irritation (5)
    29    Pica lifted grub in Sedum (8)
    30    Contest excellent goal (6)
    31    Overly into ruby related fashion again (6)
    32    Collected stone around cliffs regularly to cover bodies (13)
    1    Strike about introduction of robot that cuts coats, skirts and blouses for example (11)
    2    Minion sticking fast, nice, new plastic bags in this place (9)
    3    Inhabitant of Douglas, Massachusetts introduced to fellow Christian (7)
    5    Phantom badly upset your son (8)
    6    Miss Portman reportedly nonpareil, in a fashionable way (7)
    7    Hybrid oncidium shoot might be in this repeatedly forked ground (11)
    8    Bourgeois author wasting time becomes more sardonic (5)
    9    Recover after nil by mouth (6)
    10    Ring that has lost its fourth agate sphere (4)
    11    Abolition leads to ethanol remaining absent in a manner of speaking (11)
    16    Robe worn by old English Master presenting scrolls (9)
    18    Presses runners to take off fraction of second (8)
    22    Do lines poets composed transgress? (7)
    23    Before leaving, presents diamond watches (5)
    24    Fine burros found on sierra (6)
    25    First on street to stand up for thug in East London (6)
    26    Rust effectively smothers cereal grass (4)
To enter this competition, send your entry as an image or in list format giving the question and the  highlighted answer to before 8th August 2019. The first correct entry drawn from the hat will receive a book from the Chambers range, which has been donated by Chambers.