>>4274828You will have the most flexibility with FF because it generally offers more control over DOF and noise. DOF because you can match DOF or go shallower at the same FOV and f-stop, assuming you're taking a picture with an otherwise identical composition (distance and framing). Noise because you can generally pump iso up higher before encountering the same level of noise as crop formats, assuming you compare apples to apples. Flexibility is a good thing to have when you don't really know what you're specifically going for and what compromises you're willing to make.
There's nothing wrong with the XT5 kit but you will probably find it more limiting than the A7iv. Full frame has gotten cheap, light, and featured enough to make crop format lose a lot of their luster, and I say this with M43 as my only current camera system. FF's popularity means R&D tends to focus there.
If you ask me though, there's really no need to obsess over shallow DOF if you're trying to document reality; we don't see in bokeh. I consider ergonomics and usability the most important factor when deciding what to use.
>>4274829Then obviously they haven't worked around the limitations. Key point is that it isn't how you would have shot it, but rather how they wanted to shoot it. Some limitations can't be gotten around though, of course.
