I kinda stole your idea, and made a set of 4" pvc landing gear too. But instead of boiling my PVC and using a JIG, i just cut alittle section away from the PVC, put it in my vice & used my heatgun to straighten it alittle.
Here is my tricopter sitting on its new feet...
The rear leg mounted using two 3mm screws. I drilled and tapped the arm to accept them.
For the front arms I only used one 3mm screw & a zip-tie.
Almost ready for flight,