Take a look at this video.
I think if you lay your panels face down on a flat surface and provide some weight at each screw hole, you can get your edge pretty flush since the clamps are not going to reach into the middle of a sheet. I'd put a pocket screw every 8 - 12". (I like overkill.)
While the pocket screws will hold your sheets together tightly, you might still need additional support behind your panel.
I think if you lay your panels face down on a flat surface and provide some weight at each screw hole, you can get your edge pretty flush since the clamps are not going to reach into the middle of a sheet. I'd put a pocket screw every 8 - 12". (I like overkill.)
While the pocket screws will hold your sheets together tightly, you might still need additional support behind your panel.
