Thank you! Process involves shooting a range of images in the field (generally more than I need), then merging them in either Photoshop or a tool like Helicon Focus. I then select the edge shots (where I'd like the focus to begin and end), and then selectively edit and/or remove shots from the stack; perhaps the wind moved the subject a bit, or a bug entered shot. Following that is my usual RAW processing regime, which varies from shot to shot.
Thanks! The drop-off is something that I've struggled with using this process so far, as the edge shots will have the same shallow DoF that all of the other ones do. If there were a way to vary aperture while shooting the stack, that might be a way to do it.