By all means you should go for Rukhsati as scheduled. They only need a reason to reject or delay your case. Don't give them the chance. We were in the same situation too at one point, couldn't do Rukhsati as scheduled. But we informed Islamabad, and then did it later. However, the interesting thing is that despite the fact that I had send solid proof of our rukhsati plans to CHC, they asked me twice about the plans; once when I recieved the AOR, and second when we made case specific enquiry after sending the rukhsati proof. It hadn't been attached to our file by then. So, I would say, do not give them a reason to delay your case. We were exactly of the same school of thought as yours, but you have to act differently sometimes.