More detail for 16a - a 3 leter abbrev of 'informal' followeb by 'sinister' (in heraldic terms) minus its first letter.
17d - I should have written the letter 'heads south', not travels (travelling' isn't an indicator, it's a synonym).
The L??? R??? for "adore travelling" completely went over my head - I just couldn't see past a possible anagram given that the letters of 'adore' and L(atitude) are all present in the answer - rookie error 😡
Also, the Wiki entry on the theme is thankfully short so I had no problem seeing the words that appear in the grid and what they should be changed to:-)