When it comes to using manufactured components that have been tested, yes. I have no issues designing a custom bracket to do it, but when it comes to pre-made stuff I stick to the manufacturer's guidance. Especially Simpson. Given the scale of their operation, their ability to do this kind of testing, their obvious and unabashed profit motive, and the apparent ubiquity of this condition, if it was good for it I'm pretty sure they would have added that as a selling point by now. I'd also imagine that going outside of what a manufacturer has designed their product to do would fall below the standard of care.
Taking a quick look at the HUC hangers...they don't really publish the exact geometry but the CAD file is a decent guide. Looks like they're 16 gauge and the center of the fastener hole is about 7/8" from the concealed flanges. So you're barely allowed to consider shear at all per NDS as you're right at 3.5D for end distance (resulting in CDelta=0.5 and really neutering the strength of the connection). So you get a few hundred pounds from that. But I'd bet the real weakness is in the 16 gauge material. The fasteners in the flange going into the supporting structure a little less than 1/2' from the inside face of the hanger. I don't think it'll take much to yield the 0.07" material in that bend. Maybe 70 or 80 lbs per fastener? And you only get about half of the fasteners due to the stagger. Then you have pullover, too. Not sure where that'll end up.
So even running some basic calcs, probably not good for more than a few hundred pounds. Diaphragm chord forces are likely to be a good deal higher than that. Seems prudent to just use hardware designed for the purpose.
