good video! Makes me want to get out there! Where did you get the tower set up for your bike? I like it and it looks fairly simple compared to the full rally towers. And you are right about not wanting to take a big bike out alone. I have an 890 and feel the same way. I also have a 350 that I am thinking of making a good adventure bike out of.
That's an "Adventure Spec Mini Fairing", a Garmin Tread in a Garmin powered mount, and a few Trail Tech sensors. Nothing fancy, mainly just gets these things off of crowded handlebars. A 350 would be great for this.
These are Motoz Rallz, 15 psi, front and rear, with HD tubes. On this trip, the rear was at about 65% of its full tread depth after 2150 miles, the front still had over 90%. This kind of riding doesn't really demand much from tires (other than longish miles), but they handled everything, mud to sand to rocks to asphalt, well enough that I can't think of a reason to change to something else, so yes I would use them again, they're my go-to for this kind of riding.
It's a '21 KTM 500 EXC-F. I have an aftermarket seat (Seat Concepts Comfort XL). This bike carries all the gear I need, no problem, and comfort isn't a noticeable issue, even on long days, except on long highway hauls. It will do highway speeds all day, but it's not fun (no wind protection, bike is squirmy at those speeds, comfort is an issue), and that's where you wish you had a bigger bike. On any kind of slower, technical off-road, though, the lighter weight of the smaller bike is just a night and day difference against the bigger bikes. I wouldn't take a bigger bike off-road solo, too easy to get into a situation you need help getting out of. At "in between" speeds (easy dirt, secondary paved), big vs small doesn't make much difference, both are fine.
Any issues with doing the ride alone that you can share? Also, when in September did you do this, and what Sections did you complete? And finally, are those the Reckless 40 bags?
I rode from Grand Junction to the end of section 6 at the WY border, then did sections 6 to 3 "backwards", then back to Grand Junction. It was around the second week of September. I rented a sat phone and carried a Garmin Inreach and had somebody back home tracking me. You have to make sure your bike is well maintained, consumables (tires, brakes, clutch, air/fuel filters, etc) are fresh, carry a few reasonable spare parts and a good set of tools, and have some familiarity with basic repairs. Most importantly, you need to ride with care and make good decisions, all of which is easier when you're solo. This is still admittedly a significant risk as compared to riding in a group. I use a Mosko Reckless 80 with some other small molle bags, a small tank bag, and a light backpack. If you stay at hotels instead of camping and get all meals on the road, you could probably get away with half the gear, and you'd appreciate the lighter weight while off-road, but I like to do these trips more like backpacking, being close to self-sufficient (other than fuel and water), carrying full camping gear and most food.