Okay, I rushed out to the kitchen and made these. Here's my review:
I more or less used the recipe above, but added a couple more seasonings and did not include any salt. I also did not use fennel because for some reason I don't seem to have any.
I did not use bouillon because I don't buy that stuff. I just boiled the patties in tap water. TBH, I don't think bouillon would have added much in the way of flavor except maybe for salt, which is why I don't buy bouillon.
I used Egg Beaters because I have some that need to be used, but I'm sure two regular eggs would work equally well.
The recipe in the video above didn't specify using quick oats or old fashioned. I used old fashioned and that would be my go-to. Quick oatmeal breaks up more easily and I think would create a finer texture, so that might be a personal preference.
I used far less oil in the frying pan than shown in the video. I used a non-stick pan with just a little oil.
These were dead easy to make. I thought maybe with so little liquid it would be hard to get everything to come together but it wasn't a problem. I used an ice cream scoop and burger press to portion and press the patties, but that was overkill on both. I stopped using the burger press after the first patty. I used the scoop for all five patties just because it was already dirty, but probably won't use it again because a spoon will work just as well and be easier to clean. It was also too big. I did use a square of plastic wrap to press out each patty and form it. That worked out well for me. After I formed each patty, I picked up the bottom section of the plastic wrap and inverted the patty onto the spatula, then peeled off the plastic wrap and used the spatula to put the patty in the pan. Naturally, I did not use a hot spatula.
I browned the patties till they looked like regular sausage patties, but I think I should have made them very lightly browned instead, since they will be crisped and browned after boiling, too. How browning them less would affect how well they hang together in the boiling stage, I can't say, but they seemed very structurally sound even before browning.
I did include the boiling step and it wasn't a problem because the pan will clean up easily and I did other things in the kitchen while the patties simmered. They really don't need any attention during simmering. If anyone does make these without boiling and it works out, please let me know. I drained them using the basket that came with my pot, but I think that was overkill too and will probably just use a paper towel next time, as the person in the video did.
Even with adding red pepper flakes, black pepper, and a plethora of other spices, I thought these were a little bland, but I like food with bold flavors so YMMV.

Of course, there's no limit to the seasonings that can be added to these patties to meet personal preferences. I ate a patty on a nice HM whole wheat bun for lunch, and added wasabi sauce. It was delicious.
My patties did not achieve the crispness of meat sausages, but I think if the patties were made thinner than I made and what was made in the video, that might improve. It might also help to lightly brown them as I mentioned, so they can be browned longer the second time around, which is when they get their crispness. Using a cast iron pan might make a difference, too.
The texture was a little soft but not horrible. It seemed a bit chewy to me. Not bad enough to be off-putting, just slightly different than meat patties.
Summary: I'm excited about this recipe because I think it can be made into a reasonable facsimile of meat sausage with some further experimentation with seasonings. Any dry seasonings suggested for making HM sausage patties should work equally well with this oatmeal/egg base. The texture was acceptable. There was no oatmeal or egg flavor in these patties. Even though the patties did not get as crisp as grease-fried meat patties, there's potential for correcting that problem by shifting the frying times to less frying in the first cooking step to more frying time in the third cooking step, and using well-seasoned cast iron. Frying them in an air fryer may also make a crispier product without adding much oil.
The real test for me is whether these patties will freeze well and reheat well in the microwave. I would like to be able to cook these in bulk to have on hand for quick meals.