I am sure that airplane traveling pros have a system down for how they transport their expensive cues. perhaps many just sent it ahead to a trusted receiver using an insured mailing system - perhaps Fed Ex overnight etc.
Most infrequent air travelers who own expensive customs but want a cue for their final temporary destination are using back up less expensive cues that are placed in inexpensive back up cue cases inside larger checked bags. I have used this route without problems.
I would not do this with the more expensive customs; if I HAD to have one with me; i would ship it ahead to a trusted receiver via Fed Ex or insured priority mail. Nothing that leaves your hands is ever truly guaranteed to arrive - but you can take proper sensible caution.
Not allowing billiard cues on an airplane is a perfect example of government being the worst solution for most problems or situations in our lives. Did someone in TSA "really" envision the headline- plane hijacked with pool cue?