I don't have access to test, but given OpenAI's record on stuff like this, it would be a good idea for someone to check to see whether users can resend/intercept those requests to directly control the prompts that are sent to Dall-E without going through GPT.
Most likely they're only part of conversation history and they're unmodifiable, but I wouldn't necessarily take it as a given, and it would be quick for anyone with access who knows their way around the browser dev tools to check.