I saw a comment on an online forum recently in which a solver had objected to ‘some’ as a hidden indicator. While it transpired that they had mistaken it for a letter selection indicator, and had no issue with it in the former role, I was prompted to reassess the use of the word. I don’t think that anyone could complain about ‘some of these escorts’ as the wordplay for SEES, but what about ‘some chase escorts’? In the first instance, ‘some’ is technically an indefinite pronoun (though I would be inclined to view it as a quasi-noun), but in the second it is an adjective, and the noun which it qualifies is always generic (‘some bread’, ‘some words’). Hence in the ‘real world’ it never refers to a part of anything specific, whereas ‘some of’ always does, as in ‘some of this text’.
I’m very doubtful about the validity of this adjectival usage, and my concerns extend to other similar adjectives, such as ‘little’ and ‘most’ – again the noun-based forms ‘a little of’ and ‘most of’ are fine, but ‘a little bread’ and ‘most bread’ refer to bread generically, so ‘a little bread’ to indicate B and ‘most bread’ for MONE(y) both strike me as unsound.
Although I plan to stop using these indicators in my own clues, they are commonly seen in puzzles by a wide range of setters and rarely (if ever) seem to trouble solvers, so I hesitate to remove them from the lists on this site. Any views would be welcomed.
As you state, requiring synonymy of strict definitions precludes too many commonly-accepted replacements. Figurative language is often in broad use, and it does not seem to be a stretch to equate figurative definitions. [With that said: I would not use “gutless” to define “spineless”, as the words have the same endings. “Lacking guts” for “spineless”, however, not only works with their definitions but also suggests wordplay that is absent: a nice bit of trickery.]
All of my grids are themed, and I expend much effort in ensuring that theme words do not intersect, even when the theme is irrelevant to solving or is trivial. Even better, and even when I am likely to be the only person who notices, are grids where the themed entries are symmetrically arranged. My bride, who has no truck with cryptics (“you do you, dude”), is nevertheless the recipient of my commentary, and pretends to be happy for me when I achieve the desired effects. The look of the thing is important for our art, and art it is.
Yes, an obviously asymmetrical grid niggles setter and solver. Conditioned responses, perhaps, but conditioned all the same.