I got custom orthotics from a sports podiatrist for PF. He knew I was a tennis player. My doc got me full-length ones.
I also use some 3/4 ones I purchased from a sports store. I use these directly on the bottom of the shoe, removing the factory insole. I think the full-length ones are best for tennis because of the starting and stopping. I can use the 3/4 ones with the thickest Thorlos available, and I don't feel the need to tape them in or anything. They do squeak a lot, though.
I would suggest that you go back to your podiatrist. I think the doc should re-do your insoles so that they are full-length. My doc was of the opinion that the extra padding under the ball of the foot wasn't necessary in controlling PF, and that is probably why your doc thought the 3/4 one would be fine. The extra padding is important for tennis, IMHO, to avoid having your foot sliding around.
I think that it should not be a big deal to re-manufacture your orthotic to be full length. They would need to take the hard arch support part out and then append it to a full-length insole. If your orthotics were as expensive as mine were ($300), this seems like the least they can do to make sure you have an insole you can live with.
Do not wear the orthotic over the factory insole. I did that once and rolled my ankle a bit and toppled over. My ankles felt unstable using the orthotic in this way.