When I cook rice, I put a little salt in the pot, and all of that salt goes into the rice. But with pasta, I put a whole bunch of salt in the pot, and as far as I can tell, it doesn't affect the taste of the resulting cooked noodles much at all. Because I drain most of it off along with the excess water after the noodles are done.
The statement in your question (that salt changes the taste of the pasta more than that of the rice) sounds backwards to me. Unless it was just an error of wording, it sounds like you are (perhaps?) boiling your rice in a whole big pot of water, and draining it at the end. I know some people do make rice that way. If that is your practice, you might try another rice cooking technique in which the rice is cooked in only a small amount of water - and no draining....or use a rice cooker. If you use a method like that, plus a little experimentation (physical chemistry not needed), I'm pretty sure you could get your rice as salty as you like by adding reasonable amounts of salt, and all of it would stay with the rice.
Now for pasta, yes, you do need to drain the water at the end. Maybe someone else can provide technique for more salt absorption while cooking pasta. However, I'm not sure I get the difference between cooking-in the salt and just sprinkling it on at the end. Because the noodles are wet and contain lots of water (when done, even if al dente), won't the salt that you sprinkle on also be absorbed into the pasta??