No-improvement conjecture for coincidence post-selection

Let $\delta$ and $\epsilon$ be functions producing arbitrary real-valued outputs, and write

$$S=\delta(Z;a),\qquad T=\epsilon(Z;b).$$

Variant Task 2 accepts a pair when $|S-T|<c$ for a fixed constant $c$, rather than conditioning separately on the events $D=1$ and $E=1$ as in the original task. No improvement from coincidences. There is no gain from Variant Task 2 over the original. This conjecture concerns whether coincidence post-selection creates an advantage beyond the usual detection loophole; the paper states that this effect had not yet been analysed and presents the claim as a consensus converted into a conjecture.