Others will have better info on the details of the LOA. However to clarify, the taxation issue only comes up if you are going to or from your base. Since it is doubtful that the company would send a pilot to or from STN (where there is no flying) no imputed income should occur.
Or to put it another way, as long as the company travels a pilot to start an actual trip (AMS, GOT, FRA etc.) there should be no tax issues.