Photographer trains have to deal with step boxes just like every other railroad.
That's correct. The portable platforms idea is great for events with the public, when there are lots of passengers who are not used to getting on/off century-old equipment at relatively primitive (by today's standards) station locations. Those passengers just want to get on and off safely and easily and really don't care what things look like. On photo trains however, most of the photographers are pretty used to loading and unloading where there are next to no facilities at all. Even some of the older folks amaze me with their ability to make the big steps. Heck, I'm only 5ft. 6in. and I've yet to find a location where I can't get on without a step-box. For photo trains, the regular step-boxes are generally fine. It certainly helps to have a trainman on the ground to help the folks who are older, or perhaps carrying a lot of gear. The key thing is that when the train pushes back, there should be nothing left on the ground that is not more or less historically accurate. Equally, it is important to make sure there is nothing showing on the platforms that wouldn't have existed on a historic train.
A couple of years back, a new tourist line in south central PA decided to install permanent steps at a historic depot at which President Lincoln stopped on his way to Gettysburg in November of 1863. While I suspect that these steps do enhance the efficiency and safety of the normal tourist operations, the railroad's inability to temporarily remove them for a 2014 Carl Franz Charter pretty much spoiled this historic site as a photo location.
http://www.railpictures.net/photo/524541/The shot from the other side is even less appealing, as there are multiple yellow steps visible.
Here is the Brady shot allegedly depicting Lincoln at this location.
http://www.hanoverjunction.net/pages/lincoln.htmNo steps back in 1863.
/Kevin