I don't mind an easy LR Tuesday. Lots of first/last letter clues mixed with anagrams.

Across

1

Rebellious giant beheaded after three consecutive letters (7)
DEFIANT — DEF (three consecutive letters) gIANT (without first letter)

5

Cleans dials of several clocks on usual roster schedule (6)
SCOURS — first letters of Several Clocks On Unusual Roster Schedule

8

Chief Garbo gets into Eve's can recycling to collect rubbish (8)
SCAVENGE — anagram (recycling) of EVES CAN with G (first letter of Garbo) inside

9

Knackered captain skipped one sleep (6)
CATNAP — anagram (knackered) of CAPTAiN without i (one)

10

Bleakest remix of Drake's opening track (7)
DARKEST — anagram (remix) of DRAKES, T (first letter of track)

11

Tips return of personal assistant, along with former partners (6)
APEXES — reversal (return) of PA (personal assistant), EXES (former partners)

12

Backroad tattoos and beverages (6)
DRINKS — reversal (back) of RD (road), INKS (tattoos)

15

Obvious affair captured maiden's heart (7)
EVIDENT — EVENT (affair) with I (middle letter of maiden) inside

16

Made animal noises, cracking Wordle after first guess (7)
GROWLED — G (first letter of guess), anagram (cracking) of WORDLE

18

Slight change to meds (6)
MODEST — anagram (change) TO MEDS

20

Female cockney’s greeting to western chap (6)
FELLOW — F (female) ELLO (cockney's greeting) W (western)

21

Business with Musk revolving around Southern Comfort (7)
CONSOLE — CO (business) reversal (revolving) of ELON (Musk) around S (southern)

24

Debut book with tough puzzles purchased (6)
BOUGHT — B (first letter of book), anagram (puzzles) of TOUGH

25

They don't appreciate Dutch bank fees (8)
INGRATES — ING (Dutch bank) RATES (fees)

26

Enjoys teriyaki filling for seafood (6)
OYSTER — hidden in enjOYS TERiyaki

27

Respects someone's close encounters, overturning initial scepticism (7)
ESTEEMS — E (last letter of someone) reversal (overturning) of MEETS (encounters) S (first letter of scepticism)

Down

1

One chooses extremely dense apple drink (7)
DECIDER — DE (outer letters of dense) CIDER (apple drink)

2

Fluoride intravenously gets hospital department bill (5)
FIVER — F (fluoride) IV (intravenously) ER (hospital department)

3

Top grade hotel rewinding the last musical film (5)
ANNIE — A (top grade) reversal (rewinding) of INN (hotel) E (last letter of the)

4

Somewhat loathe a tree surgeon's place (7)
THEATRE — hidden in loaTHE A TREe

5

Occasionally stop by spy agency and ridicule slim ideology (9)
SOCIALISM — SO (odd letters of stop) CIA (spy agency) anagram (ridicule) of SLIM

6

Injured - need month in recovery (2,3,4)
ON THE MEND — anagram (injured) of NEED MONTH

7

Most natural beer interrupts sleep (7)
REALEST — ALE (beer) inside REST (sleep)

13

Spooner's Trotsky evening is illuminating (4,5)
NEON LIGHT — Spoonerism of LEON (Trotsky) NIGHT (evening)

14

"It's not fresh", last stupid waiter ignored me (9)
SALTWATER — anagram (stupid) of LAST, WAiTER without i (me)

16

Many popes finally paying annual car fee by 6-7th of January (7)
GREGORY — G (last letter of paying) REGO (annual car fee) RY (6th and 7th letters of January)

17

Say no to half-decent lyric (7)
DECLINE — DEC (half of decent) LINE (lyric)

19

Hunters observe thick tail on zebras every second (7)
SEEKERS — SEE (observe) K (last letter of thick) ERS (even letters of zebras)

22

Throw up liquor on extremely hot evening (5)
NIGHT — reversal (throw up) of GIN (liquor) HT (outside letters of hot)

23

Address for date removed entrances (5)
ORATE — fOR dATE (without first letters)