It is said that the show horse respects wood. That is quite beautiful. As a human being you could picture this as you take a stroll or a casual ride with your favorite horse through your nearby forest. This is what it means to be communing with nature. The horse is a nature loving animal and, as a gentleman or lady who loves his or her horses, you are also in love with nature. Even though your prized horse is forced to negotiate some challenging obstacles on the show jumping terrain, you never drive her too hard.
She has been well-trained. You train her respectfully each and every day. You feed her her favorite oats on a regular basis. She, as most well looked after horses do, has come to love you back. She responds well to your whispered commands and is mirthfully respondent to your clicking commands too. Because she has a great respect for wood, given the opportunity, she will jump those wooden jump poles like a true champion.
This is, after all, what you would like to achieve as a competitive show jumper. It should be part of your organizing repertoire if you are arranging events on a regular basis. Do not, for a moment, believe that vinyl poles are cheaper and more versatile than the preferred wooden alternatives. It is not pliable at all, and your horse can easily get injured if her delicate ankles clip these poles. When she senses the wood she will bound over it flawlessly.
That, of course, is quite possible in any case. It is because your champion filly has been quite well trained already. Go for wood and draw closer to nature.