I don’t recommend it unless you just want it for storage or whatever else it does out of the box. It’s basically impossible to tinker with it because it has so many layers of abstraction. At least that was my impression when I tried to edit their nginx config. It had like 2000 lines so I just gave up.
If you want a server that runs services that you download from the internet, don’t buy it. Look at it as a box that does the thing that it promises to do, not as a computer. If you want it to do a different thing, buy a different box that does that. Kinda like a TV. It’s technically a computer that runs some kind of linux but to the user it’s a monitor that also shows videos from the internet.
Also it’s perfectly fine to buy a “NAS black box” but maybe not something I’d buy if I wanted to get into selfhosting. I’d buy it if I wanted to have a NAS running at home with the least amount of “self” in “selfhosting” that’s feasable.
Dunno whether they are transcoding or not nor why they have such a bizarre setup. But I would hope 16C/32T CPU from 2017 could handle software transcoding. Also peak power consumption while playing a movie does not really matter compared to idle power consumption. What matters more is that the motherboard is probably packed with pcie slots that consume a lot of power. But to OP it probably does not matter if they use a threadripper.