...the attachment points on these trailers and the hitch receiver thingy (the mount that bolts into your pickup bed - not sure what exactly they're referred to as) were not designed for significant bends/angles that you would encounter even on relatively easy FSR's...
That's not true at all. There is a lot of articulation in 2 directions on most 5'er hitches. I use a Pullrite Superglide on my 5'er, and I've done a ton of non-paved towing with it. I regularly glamp in sand dunes, and I used to go to Pismo a lot where we had to go pretty deep into the dunes on VERY uneven surfaces to find prime spots. Here's a vid of a Superglide working:
The Superglide is unique in how it moves the trailer rearward as you turn, to avoid hitting the cab. But if you watch the vid you can see the hitch head and pivot on one axis represented by the big bolt facing you, then on an axis 90 degrees to it in the same plane which you can see as the little "saddles" with the small retaining pins on either side. Those 2 axes of motion are common to all 5'er hitches. Watch that vid for a bit, plenty of movement for basic improved roads and mild trails, or even deep dunes like I've done.
I mean, think of your average gas-station driveway, your truck is in it way before the trailer, and the truck is probably climbing and moving on an angle while the trailer is out on the "flat" road. The hitch has to allow that even for pavement duty.
Still, I personally wouldn't want something as big as even the smallest 5'er you'll find for "Overlanding." Again, I pull my trailer pretty far off paved roads, but I don't consider that Overlanding. I don't really have any great shots of it off the pavement, but here's one where you can see the ample clearance between the bed-rail and trailer:
This is one of my previous trailers, but I think this one was a few miles out a dirt/gravel road:
Again, previous trailer, but out on the sand:
These are some pics I had from when a previous Superglide bound-up, causing it to bend the top plate of the head, but you can see the big bolt that attaches the head and allows pivot "side to side" in this pic:
And this is one of the "saddles" where the head rides to pivot "front to back":
This kind of gives you an idea of where we go to camp, we go down a long stretch of hard-pack like this (this would have been going out, since the Ocean is on my left) and then you turn into the dunes into the soft sand and have to be able to handle the dips and rises to get away from the crowd down on the hardpack (that always seem to come in at low-tide, then start getting flooded as the tide rises and it's a total s-show as they scramble for higher ground... we just start up high):
Glamis, setup in the sand, not far from the road but some good dips and stuff to get to this spot:
I can tell these pics are old by how stock my truck looks, lol. But if you look in the distance in this pic you can see more of the rolling dunes we often pull through, obviously all the pics at "camp" look flat because we pick flat spots to camp:
Anyway, I'm not saying it's hardcore offroading, but the angles can get pretty high as you're moving through dunes. And I've also done lots and lots of miles on forest service roads with the 5'er going to places like Moonrocks. Personally, I would have ZERO interest in actually "Overlanding" with a 5'er, at least by my deffinition of Overlanding (which doesn't involve 3 ACs, heat, 150 gallons of fresh water, satellite TV with 3 TVs including one outside, full kitchen, full bathroom, etc. like my 5'er has).
Please understand I mean NO offense by this, but have you owned/used a 5'er? If not, and you're not actually familiar with them why would you tell the OP what they are or are not designed for and can or cannot do?
-TJ
