What level of detail should this plan contain? Too much detail and you give away our negotiating position and tie the negotiators hands; too little and people will complain about lack of detail. Would you accept a plan which comes with the caveat that compromise and negotiation means that none of the plan may work out the way it is described? What about a plan that changes on a weekly basis due to circumstances and negotiation?

I don't believe it is possible to provide a plan that will satisfy people who want to remain in the EU, and I believe that people who want to remain in the EU and are asking for a plan know this well.

You're not going to get the plan you want. A vague overview of goals is the best you can hope for, and exactly what you've been given.