The parts themselves appear to be of good build quality. Will post an update, regarding how the parts fit together, after I assemble the unit.
@Don Fairbanks and anyone else interested...
I had some activities going on so I didn't complete assembly tonight. I also lost some time being confused by which knobs were supposed to be 1, 2, and 3 per the printed instructions. Will get back on it tomorrow. I only got as far as attempting to bolt the main frame to the front and end base units, and bolting on the footplate.
What I can report is the main frame, base units, and footplate are all heavy AF. Maybe they're light to someone built like The Mountain from Game of Thrones - I am nothing like that person.
The fit between the main frame and the base units is very tight. I had to pound each base unit into place with palm strikes/hammer fists before I could start inserting the bolts. The nuts and bolts can be screwed together by hand maybe 5% of the way, then the provided tools must be used to finish the job - very tight fit.
My back started feeling the effects of lifting these heavy parts and assembly. Reminds of when I had to lift my Mom's luggage to and and from the airline check-in desk at the airport, because we were trying to get both pieces under the weight limit. Lot of weighing the luggage piece, then taking it back and moving items between the 2 pieces to get the weight even and both under the limit. My back was so sore the next day.
So to try to compensate, I took a fair number of breaks for Fast And Loose type drills, hip rotations, ATG split squats on the stairs to stretch the hip flexors, etc. After I called it for the night, I spent some time with lateral stretches on a door frame and cobra pose. I might still wake up tomorrow with my low back feeling terrible but at least I tried.
So in conclusion, I think the Freak Athlete Nordic Hyper GHD is not built to be a lightweight thing that will collapse under a guy like The Mountain. Heavy AF, with parts that fit together tightly, and bolts that take effort to secure. I'm confident that a properly assembled unit will support huge, heavy guy like that day after day, for years on end, without issue.
Assembly video for the curious