I just ran into this one as well.
My owner wanted to visit an airport short notice not listed on the current waiver. Our Ops had to resubmit the waiver driven by FDC NOTAM 3/2768; to their credit and the FAA/TSA system involved, it took less than 24 hours (instead of the 5 business days mentioned on the website).
I'm guessing that your waiver has to mention exactly the departure and destination airports, so KLAS has to be there.
This seemed the clearest document out there
http://d.universalweather.com/pdf/tr...ss_Program.pdf
What CBP exemption are you referring to?
And I find the whole concept mind boggling in the country that invented business aviation. As a general observation, I almost despair of trying to keep track of all the myriad requirements that the TSA, FAA, CBP and several other agencies seek to make me as the PIC responsible for. Every time I have a US trip (couple of times a year), the stress increases significantly, looking for what trap I have missed this time. Give me Moscow any day of the week instead