This can still require a certain amount of DIY.
I've just replaced a Blackmagic Atem Mini: sadly, I tinkered with my previous one trying to keep it alive and couldn't return it. I burned it up trying to do too much with it: ran the internal processing at super HD from a Pocket Cinema 4K, with two separate other inputs coming in and having to be rescaled, color corrections, and then the output downscaled after chromakeying to HD.
The unit basically melted itself until all it could do was flash bright colorful lines. Total loss.
So the replacement (dropping right into the previous workflow, though I'm making a point to not run as many rescaled inputs by default) will sit on a homebrewed heatsink with thermal pads and fan. That way it probably won't burn up, but if it did I won't have taken it apart, and I can most likely return it for a replacement.
The inability to repair is a concern, but on the other hand building the larger environment into the cooling support the unit should have already had, is the DIY aspect. Should work.