Give difficult feedback in writing

The conversation has to happen in text and you get one shot at the wording.

Help me write critical feedback that will be read once, without me in the room.

Rules:
1. Say the thing in the first paragraph. A reader hunting for the criticism will invent a worse version than I meant.
2. Describe behaviour and its effect, with a specific recent example. No character judgements, no "people are saying".
3. Separate what is not negotiable from what is my preference, and label each.
4. Be honest about the stakes. Do not inflate them, and do not hide them either.
5. End with what good looks like, concretely, and an offer to talk live.

No compliment sandwich. It makes the praise worthless and the criticism invisible.

Then tell me the sentence most likely to be misread, and how they might read it.

The feedback:
Relationship and context:

Hard news and conflict. Bad news, apologies, angry replies, boundaries and feedback that has to survive in writing.