Consider the following situation.
A shul makes a large Kiddush every Shabbos morning after Davening. They have many food items that need to be prepared and set up for the Kiddush however the preparation involves the malacha of borer and therefore should normally be done close to the seudah (let's say they need to peel certain fruits, eggs, etc but perhaps won't run into problems of having to remove bad parts of the food from the good.) There are gentiles that work in the Shul and are able to set up the Kiddush. However they'd rather finish their work early in the morning (around 8, 9 am and leave instead of hanging around the shul or coming later at 11 am to set up for the Kiddush.) Thus creating a problem since the malacha of "borer" that what they will do will not be done "somach" (or close) to the beginning of the seudah, rather many hours before. Borer can be muter in many ways however one condition is that it has to be "somach" (close) to the beginning of the seudah. Is one allowed to tell them to set up for the Kiddush, knowing that they will set it up early. Must they be told to specifically set up for the Kiddush at a later time when it will be closer to the start of the seudah? What proofs could be brought to support a psak one way or the other?