1ACross Fifth Aniversary Puzzle

A new venture to the Subcontinent with a submission to an Indian crossword group called 1ACross.  Sowmya Ramkumar recently posted on Derk Harrison's Crossword Centre Facebook page announcing the imminent fifth anniversary of their club, occurring on 10th August 2019 and asked for crosswords to be sent to them.  So Eclogue duly obliged.

The crossword became part of their booklet to celebrate the fifth anniversary of the group which comprised 21 puzzles submitted by various compilers from acros the world but primarily India.  So, starting in early August 1ACross began publishing one of these puzzles each days as an interactive competition puzzle, calling it the Gridfest and Eclogue's contribution appeared on the 20th August 2019 as Grid No. 11.

The puzzle's preamble read:

In every clue, the definitions are to the entry, but a thematic letter is ignored in the wordplay wherever it occurs.

1ACross Fifth Anniversary Puzzle solution grid

The puzzle's title held a hint in that the fifth letter of the word "ANNIVERSARY" is "V".
Thus the solution grid's postamble stated:
Every entry begins with (and occasionally contains) a “V” being the Roman Numeral for Five, to celebrate the fifth anniversary of 1ACross.

Some feedback was received from the first solver which stated "My compliments to today’s setter. Fab grid, no small feat of construction. Beautiful clues, all kosher. Spoilt for choice picking top 3. But for the theme letter device (became obvious quickly) would have been more difficult. Could not anno VANESSA".

This puzzle was voted into second spot amongst the solvers' favourites being pipped to the top spot by Sowmya's own puzzle.
It must also be noted that Keith Williams secured joint first place as best solver, returning 21 perfect grids.

After the Gridfest the puzzles were collated in a book and published by Sowmya via Amazon as both a Kindle book and also in paperback.

Sort

SORT was published in the August 2019 issue of Crossword 496, the preamble goes:

Six symmetrically placed across solutions, whose unchecked letters could provide the title, should be read together to indicate how solvers must replace them.  Every clue generates an extra letter in wordplay not used by the solution.  In clue order these extra letters spell out a further instruction.

Solution Grids

Final Grid

Initial Grid

Solvers were required to select six symmetrically placed across entries (with SORT as their only unchecked letters) which provided a coherent instruction.  These were USER, OMAN, NUMB, ERIN, GINS and TEAD.  When concatenated, these provide the instruction, “USE ROMAN NUMBERING INSTEAD”.  Each of the six entries should be replaced by the four letter equivalent of their clue number.  Extra letters in wordplay spell HIGHLIGHT SUM OF REPLACED ENTRIES FOUND IN STRAIGHT LINE.  The sum of the six new entries is 17+22+24+26+29+35 = 153, which can be found (also in roman numerals) in a straight line in the NW corner of the grid (CLIII).