I see. Well, let's say that at some point you will want to put on.....uhhh...a real suppressor. Alignment of the "can" is critical. With a .22lr you won't have as much of a serious consequence with a baffle strike as you would a high powered rifle....usually. All it takes is the ONE time that the baffle strike is serious, and you'll be lucky if only your "can" is destroyed. Compounding the issue is the use of one of these "couplers". Let's say that Ruger did a perfect job on their machining practices (which they don't; that's why everyone uses tolerances), and that the threading on a professionally threaded barrel is also perfect. Most real suppressors still maintain an average of .030"-.040" over the bore diameter of the weapon. That usually depends on near perfect threads.
With the couplers you have significantly increased the chance of injury/damage. Here's why. First, is the outside diameter of the barrel perfectly concentric to the bore of the rifle? Not usually. There's a tolerance that is allowed by the factory. Second, is the inside diameter of the coupler perfectly concentric to the threading on the coupler? Not usually (tolerances). Third, is the threading on the coupler perfectly concentric to the threading on the can? Same answer. Finally, is the inside diameter of the coupler a perfectly tight fit to the outside diameter of the rifle? Almost always no. That's why example #1 that you listed has a slip ring nut to tighten it down. Now this is all important, and still doesn't take into account machining imperfections (burrs, bumps, gouges, etc.). If there are any other issues, like angles of muzzle crown or a loose fit overall, these can spell real disaster for you.
Let's say that all issues aside except for one thread angle being off and one concentricity being off, everything else is acceptable. If your threading is off by 1 degree in angle and your can is 4 inches long, your suppressor bore would be .0698" (pi rounded at 3.14159 x diameter of 8 / 360 = .0698" mathematicians tell me if I screwed this up, I'm tired). Now if the tolerance was an industry standard of +/- .001", you could conceivably have a nice roundish number of .0708" off center of the barrel bore at the suppressor bore. Even though the suppressor allows for .030"-.040" over the diameter, that only gives you .015"-.020" of wiggle room. Now we're well within the range of consistent baffle strikes.
Example #1 that you listed states-
Serious injury or death may occur if the bullet path is not clear. If unsure, please consult a gunsmith before attaching this accessory to your weapon. A simple alignment check is to remove the barrel from the gun, attach the coupling and suppressor, and look down the bore from the chamber end to ensure that the baffle edges cannot be seen.
This is probably their legal way of saying that they know their product is not one size fits all. You will most likely need a gunsmith to install it correctly. At the price for their product and a gunsmith installation, you could have your barrel threaded. Also, their "simple alignment check" is inaccurate at best. If you move your head around while looking down the bore the angles will all change. And if you can look down the bore at any angle and "ensure that the baffle edges cannot be seen", you probably have a suppressor that is going to be inefficient. The goal is to get the suppressor baffles and blast baffle to be as close to the diameter of the bullet as possible without any baffle strikes. The further the baffles are from the bullet diameter (generally speaking), the less efficient the suppressor is at suppressing noise.
I hope this has helped you. It's not my intention to shoot down your idea (pun intended), but I'd rather see you safely shooting into the distant future and not ruin your investment. I know this is just for a....uhhh...fake suppressor, and it might work well for one of those. Just be safe with your decision.
