The secret is not to have the 4 screws tightened down too much, or else it makes it very difficult to clip in and out. Loosen the screws just a little bit and see if that makes it easier. I've been using Speedplay Zeros for several years and just put on a new pair of cleats. Tried them on the trainer and it was scary-difficult clipping in and unclipping. I could barely clip in or out. I backed off the screws just a bit and it was much easier to clip in and out. Then I clipped in and unclipped for a few minutes and they're almost perfect now.
I love my Speedplays.