The Sunday Crossword No 3106, Sunday 28 Jun 2020

ACROSS
1   In conversation, nag perhaps is grating (6) HOARSE (~horse)
4   Soldier getting into old woman's starter of entrails, wanting seconds and offal dishes (8) HAGGISES {HAG{GI}S}{En...s}{S}

9   Stir an army, to some extent, somewhere in Albania (6) TIRANA [T]
10 Spooner's fervent penguin perhaps gets soy paste (4,4) BEAN CURD (~ keen bird)

12 'A fancy ship'? That's a joke (3-5) ONE-LINER [DD] (Addendum - {ONE}{LINER} - See comments)
13 Lousy fool about to show respect? On the contrary (3-3) TWO-BIT {TI{BOW<=}IT}
15 You're telling me to wink and nod manically before Congress (4,1,4,2) DONT I KNOW IT {TO+WINK+NOD}{IT}
18 I'll eat gelato endlessly, voraciously (it's Italian fare) (11) TAGLIATELLE {ILL+EAT+GELATo}*

21 Mostly regressive rule suppressing the theologian (6) LUTHER {RULe}<= over {THE}
22 Injured veteran English respect (8) VENERATE {VETERAN+E}*
24 A German refused caffeinated concoction: 'This is not skinny' (3-5) FAT-FACED {CAFFeinATED}*
25 Eat too much, and sulk about hollow icing (3,3) PIG OUT {P{IcinG}OUT}
26 Seek damages about Scandinavians becoming members of African Union (8) SUDANESE {SU{DANES}E}
27 Slider prepared for lazy folk (6) IDLERS*

DOWN
1   Drink offering cold comfort? (3,5) HOT TODDY [CD]

2   One wearing green with silver trim, going well together (8) AGREEING {A{GREE{1}N}G}
3   Thin, asinine grin displayed in Hollywood musical (6,2,3,4) SINGIN IN THE RAIN*

5   Primarily: 'Agreed! Manifestly! Endorsed! Naturally!' (4) AMEN Acrostic &lit
6   We don't weigh thin comic for Hollywood drama (4,4,3,4) GONE WITH THE WIND*

7   He painted horses, mostly fat, on a ship (6) STUBBS {S{TUBBy}S}
8   Some caused a terrifying calm (6) SEDATE [T]
11 Before start of Epsom, support horse that's old (13-19 years) (7) TEENAGE {{Ep..m} under {TEE}{NAG}
14 Expected to be amazed when taking in little island (7) AWAITED {AW{A{Is...d}T}ED} (Addendum - {AW{AIT}ED} - See comments)
16 Poultry served in beer for hoodlum (2,6) AL CAPONE {AL{CAPON}E} Appearing in full for a change in Crosswords.
17 Reminders of monsieur being passionate, stone me! (8) MEMENTOS* {M}{MOMENTS*}
19 Isn't honest with banks (6) BLUFFS [DD]
20 Said 'Full!' having swallowed a bit of tomato (6) STATED {S{To...o}ATED}
23 Goes with 'Look up!' (4) SEES [DD] (Addendum - WEES {W}{SEE<=} - See comments)

Reference List
Soldier = GI, Second = S, Congress = IT, English = E, A in German = EIN, Ship = SS, Support = TEE, Monsieur = M, With = W