Traders don't read your design rationale. They see a screen during market hours and decide, in under a second, whether this platform looks like it knows what it's doing.
That judgement isn't made on features. It's made on whether the numbers line up, whether a panel jumps when data refreshes, whether the button sits where the eye already went. On the web platform I owned, the complaints that tracked with our NPS were rarely “this is missing”. They were “this feels clumsy”.
Which is why I stopped accepting the first design. Not because our designers weren't good — they were — but because the first version is the one that solves the brief, and the second is the one that solves the feel. The gap between them is where perceived quality lives.
What I learned to look for, roughly in order of what it cost us: flicker on refresh, misalignment between adjacent panels, inconsistent spacing between a label and its value, and the same action sitting in different places on two screens. None of these appear in a PRD. All of them come back as a ticket that says “the site is confusing”.
Hierarchy and decluttering are table stakes; any competent reviewer catches those. Being anal about alignment and adjacency is what separates a screen people tolerate from one they trust with money. If a design is merely good, someone with an open position will notice.