After making a semi-large synth last night, I discovered an ugly truth. When sorting the slideshow by filename and you include photos with differing numbers of digits in them (in my case three digit numbers, example: Walking Bridge 117.jpg, and four digit numbers, example: Walking Bridge 1,117 are not counted as numbers, but rather sorted from left to right, thus the larger number is sorted first because it begins with 111 and the smaller number is judged second because it begins with 117.
I recognize that this likely seems like a fringe case to you, especially as you frequently advise against very large synths, but it matters to me. Yes, I could batch rename 999 photos to include a '0' before the three digit numbers and resynth, but... it was much easier to come say that the viewer's sorting should be changed. =]
I'm still holding out hope for sorting by EXIF date taken, which would also solve this problem with much less work.