The stick-in-ground weave poles I ordered arrived today. So we took the first step toward fixing Zap's weave problem. The poles are light weight so I can easily bring them with me to train in new locations.
Watching some videos of Zap weaving in slow-mo revealed something I had not seen before. With his current rhythm Zap bends his body around three poles at the same time (almost 3½ if you include his tail) - no wonder he's having trouble!
I will post a video of Zap's first go using the channel method later.