Yes, your thoughts on the install are right on. Start with the functional length between the K and the LCA being the same as with the stock strut rods for the adjustable strut rod and work from there. You want the LCA to be perpendicular to the frame, and you want it to be free of any binding when it travels up and down. Adjustable strut rods are not for adjusting the alignment specs, although you may see a change in the alignment numbers after installing them. The goal is the free movement of the LCA up and down, while reducing movement fore/aft.
You'll want to have as much of the suspension installed as possible while still being able to check for resistance/binding. So, torsion bars in, UCA's, spindle, LCA's installed. You'll need to removed the torsion bar adjusters so you can cycle the LCA up and down by hand. You'll also need the shocks out, and if you have a front sway bar you will want that disconnected as well. Then cycle the suspension up and down, from bump stop to bump stop, and check for binding. If you know where in the range of travel your ride height is that will be better too, since you'll want that to be the neutral spot. It takes a little trial and error, especially the first time, to get a feel for what is normal resistance and what is binding. When you think you have it good, put another turn on the adjustment in one direction or the other and see what that does. If you're right, it should be more binding, if you're not, you may get less.
I've found with my cars that the adjustable strut rod ends up being a bit shorter than the factory strut rod, but I also use Delrin or poly LCA bushings, so the LCA may be slightly farther forward with that arrangement than with the stock bushings.
Adding the adjustable strut rods will not make the ride harsher. If anything, it should smooth it out. The strut rods should not be affecting the up and down travel of the LCA, this is especially true for the adjustable strut rods. So the ride quality shouldn't change. What does change is the amount of forward/backward movement the LCA can have under acceleration and braking. That directly moves the lower ball joint, which means caster changes. With the adjustable strut rod there shouldn't be any forward and backward movement, except for the tiny amount built into the changes in the arc when the strut rods moves up and down. But that's at an angle to the LCA too.
This isn't my video, another member took this of his LCA and strut rod. It shows how much movement there is with the factory arrangement. This is just a drive around the block and a slow speed stop. Watch the front end of the strut rod, and how much it moves around. That's all fore/aft movement in the LCA. IMO, the adjustable strut rods are a great addition even if everything else is stock. It will reduce that caster change, making the handling much more accurate, without affecting ride quality.
✂️ Strut rod deflection