Pretty enjoyable! Nothing hugely remarkable, positively or negatively, just a pleasant solve.

Across

1

(& 11-across) P.S. Bluey lego unfortunately fails completely (4,5,2)
GOES BELLY UP — anagram (unfortunately) of PS BLUEY LEGO

3

Someone sculling after audible complaint by key vineyard worker (10)
WINEGROWER — ROWER (someone sculling) after homophone of WHINE (complaint), G (key)

10

Tech firm brief: frames are wearables? (7)
APPAREL — APPLe (tech firm without last letter) around (frames) ARE

12

Estimate based on what's known to repeal tax, roughly (11)
EXTRAPOLATE — anagram (roughly) of TO REPEAL TAX

13

Finishes doctorate, leading to self-importance (3)
EGO — last letters of doctoratE leadinG tO

14

Unbounded chat, like our kind of poetry (5)
HAIKU — cHAt lIKe oUr without outside letters

15

Main truth is verbalised (9)
PRINCIPAL — homophone of PRINCIPLE (truth)

17

I'll be there for you, for example, when new home gets trashed (5,4)
THEME SONG — anagram (trashed) of N (new) HOME GETS

18

Party has dumped last top dog (5)
ALPHA — ALP (party) HAs (without last letter)

19

Sign seen regularly back in Rozelle (3)
LEO — reversal (back) of even letters of rOzElLe

21

Shut away, become angry about search (11)
SEQUESTERED — SEE RED (become angry) around QUEST (search)

24

A treat with a cuppa for Spooner's main lesson (7)
TEACAKE — Spoonerism of KEY TAKE (main lesson)

25

Ripped off opening after promotion for Twister (7)
TORNADO — TORN (ripped) AD (promotion) O (first letter of off)

26

Cunning, nabbing Neptune's spear in a forceful way (10)
STRIDENTLY — SLY (cunning) around TRIDENT (Neptune's spear)

27

Miss commonly seen by building site (4)
SKIP — double def.

Down

1

Solemn accent (5)
GRAVE — double def.

2

Course hampered by not initially dying to share feelings (9)
EMPATHISE — PATH (course) inside dEMISE (dying without first letter)

4

Icehouse hit unpacked melancholy mostly (5)
IGLOO — I (middle letter of hit) GLOOm (melancholy, without last letter)

5

Hugging me back, bold and dashing (9)
EMBRACING — reversal (back) of ME, B (bold) RACING (dashing)

6

Mistakenly recalls rooster rides (6-8)
ROLLER-COASTERS — anagram (mistakenly) of RECALLS ROOSTER

7

Western actor with rising Irish singer (5)
WAYNE — W (with) reversal (rising) of ENYA (Irish singer)

8

Plain rope coiled in Melbourne suburb (9)
RIPPONLEA — anagram (coiled) of PLAIN ROPE

9

Step over certain slain crook in classic tale (8,6)
TREASURE ISLAND — TREAD (step) around SURE (certain) anagram (crook) of SLAIN

14

Frazzled host leapt to place pans here (9)
HOTPLATES — anagram (frazzled) of HOST LEAPT

15

One formally crowned by peers? (4,5)
PROM QUEEN — cryptic def.

16

For each degree, enters store for book (9)
PAPERBACK — PER (for each) BA (degree) inside PACK (store)

20

Deb abandons sophisticated broadcasting (2,3)
ON AIR — debONAIR (sophisticated) without deb

22

Next oldest's partial to praise (5)
EXTOL — hidden in nEXT OLdest

23

Broke up after first date slump (5)
DROOP — D (first letter of date) reversal (up) of POOR (broke)