This is what I was referring too specifically."hunched-over a bit, neck bent over". As you stated, unless out of a pick up or table, we all have to either pick up, roll or lift onto the beam when using horizontal. When I stand erect. My elbows are at 47 inches. When I carry I've found walking straight up gives me less back problems. If I can eliminate leaning over one more time to split that is an advantage to me. Trust me, we have a 3 point splitter as well that I could try all different levels and what is the best for me is 40 inches high.
When splitting large round multiple times, with no tables, I was leaning constantly trying to lift MULTIPLE times more than I do now. Putting half of the split back on the rail once it fell off after resplitting the first half. My back is WAY better at the end of the day and that's what is important to me. That was my scientific experiment and no back issues now. I'm near 50 and was planning for the future to be able to do this by myself. My dad who is 77 and works along beside me agrees. Granted, I am slower by myself as opposed to 2, but I handle some pretty large stuff with my setup which is what it was made for. Again, personal preference on how you decide to "gather and split" comes into play here. I just know my back would actually get spasms when I used the 3 point low to roll big ones on. When doing 24 inch long 4 ft round beech it takes 2 guys(for me at least) to roll them around and up on the rail. We used a ramp but you still strain a lot. Now, once I pick up a 4ft round ONCE, it never hits the ground again till all the pieces are to size.
I run a full auto cycle as well and like it. I would not be comfortable having someone else run it though. As you said, you can be getting ready for the next one if you are pieced to size or dealing with small stuff.
How high is the top of your beam? Our old stationary splitter was 24" and it was too low for me as well. My fingertips are 30" off the ground when walking straight up so maybe that is another factor. I'm not picking a fight with you, as I stated earlier, Just offering different ways of doing the same thing so others can have options.
Over the years I've helped people in wood gathering at their location and just go along with their method. You gain a little info quickly if something works or not, just as I have done looking around on this site. Horizontal, vertical, electric, noodle, Fiskars debates will always be that,,,,debates.
Have you tried the new Fiskars electric?