The Comprehensive Economic and Trade Agreement between Canada and the European Union has often been cited as an example. It's said to favour western beef at the expense of cheese. Canada said it was prepared to open a few small breaches, to accept a few small adjustments in percentage, because that would allow it to make considerable progress.
However, as we've clearly seen, the European market is closed anyway due to non-tariff barriers. In the end, it won't even have produced the desired effect.
Personally, whenever I hear people say not to put all the cards on the table and to keep the door open, I fear that this is just a way of saying that they're prepared to sacrifice little pieces yet again.
Are you drawing the same conclusion as I am?