IMO, no problem with the registration as potential buyer will buy the car & time wasters will not buy even if it is Isb, Khi or Lhr registered. I had a margalla which was faisalabad registered & so many people were degrading it but i sold it very easily. Then had a lahore registered baleno & many people said that Lhr number has got lesser resale as compared to Isb registration but that too was sold in just 2 days after posting ad on PW.
However demand is extremely high, keep that in mind.