Solution to Right is Wrong by Flowerman

 Right is Wrong by Flowerman - SOLUTION

In the twenty extra words, there are ten showing the pattern of two consecutive letters of the alphabet, and ten showing the pattern of two consecutive letters in reverse order. Entries provide five additional examples of the former pattern, meaning that ten examples are still available for the final requirement. They also provide seven additional examples of the latter pattern, meaning that there are eight examples still available.  At this point, potentially either pattern could be the particular one needed to enable completion of the puzzle. However, only examples of the reverse order pattern can replace letters in perimeter cells such that all new entries in the grid are real words. 

The title suggests which is the particular pattern to enable completion of the puzzle: “right”, ie correct, is the reverse pattern as exemplified by ON in WRONG, while the forward pattern as exemplified by GH in RIGHT is “wrong”.

Initial grid

Final grid.

Explanations

For across clues, extra words are shown after the entry. The relevant 2-letter pattern is shown in square brackets.

Across

1 HOUMMOS                  ca[fe]                    MUSH(r)OOM*

6 IDEATE                          [vu]lgar                 I D(uk)E ATE

10 ASSIGN                       [po]licy                 (S(pooner) GAINS)*

11 TRISTE                                                       ("tea" RITE) around S

14 FUROR                                                      FUR O R

15 LARI                             bijoux                   (spectacu)LAR I(n)

16 TEARS                                                       E in TARS

18 LUBES                         Wolfgang             SUB(t)LE*

19 WREAKS                     solemn                 (S(tage-struc)K W ARE)*

21 GENRES                      Rajkot                   NR in GEES

23 ARABICA                     fo[lk]                     A RABI(d) CA

24 JIGGLE                         churc[hg]oing      J (n)IGGLE(d)

25 ANEMONE FISH         top-quality           (E MEN FASHION)*

29 NATTER                       meanin[gf]ul        REAGAN< with TT for A G

31 SCORNED                    Ma[cb]eth            CRONES* D

33 PANNES                      sexy                      P SENNA<

35 TEWITS                       lo[wv]eld              (WEST I(n)t(o))*

37 NASAL                         loc[kj]aw              (LAS AN)<

41 SACRA                         cocc[yx]                (ACR(os)S* A

43 GITS                            anecdotes            GI(f)TS

44 UNDER                                                      (ch)UNDER

45 SEALCH                                                     SEARCH with R becoming L

46 REDCAR                      hubcaps               RED CAR

47 RESCUE                       QR-code               RES CUE

48 UNHANDS                  Byzantine             (NUNS HAD)*

 

Down

1 HALT                             (c)H(art) ALT

2 OSIER                            O RISE*

3 MIHRAB                        BAM< around (I HR)

4 ONUS                            (b)ONUS

5 STRIG                            (cross-section’)S TRIG(onal)

6 IRON                              NORI<

7 DIRL                               LaIRD*

8 ATABEG                        (A BEG) around TA

9 TERES                            (af)TER ES(timates)

12 MISREADS                  (SIRE DAMS)*

13 PAEAN                        PA(g)EAN(t)

15 LURGI                          IRREGULAR* - RARE*

17 SKIM                           (e)SKIM(o)

19 WARNINGS                N in (WAR IN GS)

20 SCORE                         SCARE with A replaced by O

22 EJECT                           C(arp) in (E JET)

26 ETNAS                         (A(re) SENT)*

27 FOES                           OF< ES

28 SNICK                          SN (qu)ICK

30 TASTES                        (SET(h) SAT)<

32 RWANDA                    W in (R AND A)

33 PAISE                          P(r)AISE

34 SADHU                        SAD H(ind)U

36 TREAD                         (philatelis)T READ

38 LULU                           (hopef)UL UL(timately)<

39 ANCE                           ANC(l)E

40 TERN                           "turn"

42 AIRS                            (ch)AIRS