No 12854, Monday 10 Feb 2020, Gridman

Most unlke Gridman to use a Grid with 'unches'? Has he used this grid before? Stumped by 18D.

ACROSS
1   Get on with winner, setter and dandy (3,2,3) HIT IT OFF {HIT}{I}{TOFF}
5   Stick with island politician’s drink (6) IMPALE {I}{MP}{ALE}
9   Model makes standard jibe in the morning (8) PARADIGM {PAR}{A{DIG}M}
10 Almost obstruct alliance (4) BLOC BLOCk
12 Issue that US newsmagazine recalled (4) EMIT<=
13 Where different cultures blend, there emerges top (7,3) MELTING POT {TOP}* [RA]
15 Long-suffering sort, gentleman is creative at heart (6) MARTYR {M{ARTY}R}
17 Three points awarded to May without a contender (5) ENEMY {E N E}{MaY}
19 Dangerous sub starts uttering bloody objectionable, atrocious threats (1-4) U-BOAT Acrostic
20 More rubicund international misses the steering aid (6) RUDDER RUDDiER
23 Nothing unusually posh in journeys made in these vessels (10) TROOPSHIPS {TR{0}{POSH}*IPS}
26 Reportedly unhurried in finding berry (4) SLOE (~slow)

28 Goa's roving guide at start is excited (4) AGOG {GOA}*{Gu..e}
29 Unfair arrangement in the tailor’s (6-2) STITCH-UP [DD]
30 Hate revolutionary journalist’s examination (6) DETEST {ED<=}{TEST}
31 Bold strip drawn over Indian press employee (8) SPIRITED {SP{I}RIT*}{ED}

DOWN
1   Mark takes part in face-off (6) HYPHEN Rebus
2   Trade Union’s rule to alternate guild is extended (6) TURGID {TU}{R}{GuIlD}
3   With time, it waits for no man (4) TIDE [GK]
4   Musical composition is limited enjoyment to way-out visitor (5) FUGUE {FUn}{GUEst}
6   Male edges to single cut fruit (5) MELON {MalE}{LONe}
7   Welcomed a duplicate record by Edward (8) ACCEPTED {A}{CC}{EP}{TED}
8   Understanding eastern master’s course to basic yoga (7) EMPATHY {E}{M}{PATH}{Yoga}
11 Celebrity hurls back expletive (4) STAR<=
14 Scurry by American lawyer extremely redundant (4) DART {DA}{Re...nT}
16 Fifty per cent of us heard a letter (3) YOU (~u)
17 Hardly bumpy match is pared down (4) EVEN EVENt
18 Boy has nil complaint against strength-increasing drug (8) ?O?O?A?T (Addendum - ROBORANT - {ROB}{0}{RANT} - See comments)
19 Said bishop left milk product for hungry Enid (7) UTTERED {bUTTER}{EniD
20 Russian company personnel in German industrial region (4) RUHR {RU}{HR}
21 Had lot to be thrown as outdated... (3-3) OLD-HAT*
22 ....Chief gathers tops of plastic empties in a pile.. (6) HEAPED {HEA{Pl...c}{Em...s}D}
24 Saintly one in terrible soup (5) PIOUS {P{1}OUS*}
25 Built in whichever direction (3,2) PUT UP<=>
27 Show sign of life — just fair by half (4) STIR {juST}{faIR}

Reference List
Setter = I, Island = I, Standard = PAR, Points = E, N, International = I, Nothing = 0, Journalist = ED, Indian = I, Rule = R, Duplicate = CC, Record = EP, Eastern = E, Master = M, Boy = ROB, Bishop = B

Dr RKE's TalePiece

Battle of Bosphorous

The ENEMY is about to strike the TROOPSHIP of the Allies from the STARboard side, unseen from a U-BOAT (the HYPHEN hides the German word for 'undersea'). Because of the TURGID waters of the returning TIDE, the ship has  PUT UP its RUDDERs and cannot steer clear of danger. To make it worse, the U-boat is made of the strong steel from the RUHR and it does not EMIT any signal being invisible even to the radar.

In the ship is a MELTING POT of navymen from different nations which have STITCHed UP an alliance to stop the Nazi BLOC from winning.The naval surgeon has fortified them with a ROBORANT made from MELON and SLOE and so they have become SPIRITED enough despite having only DARTs to IMPALE the enemy with and no other wortwhile ammo. The PIOUS among them pray for providence, the novices are AGOG with excitement and the OLD HATS in a FUGUE state but there is good EMPATHY among them and they HIT IT OFF well, sharing a common DETEST for losing.  EVEN before YOU have UTTERED Jack Robinson, they change their attack PARADIGM from the ACCEPTED one to something most unconventional and manage to overcome the U-boat, losing very few men. Those MARTYRed in this epic battle have praise HEAPED upon them by Rear Admiral Sir GRIDMAN SETTER, VC (CV<=)