For me, it's a matter of timing. I don't consider pasta stable enough to let it sit. It will either keep cooking and turn to mush or it will stick together in one giant mass of starch... particularly if you're using fine pasta like capellini.
I do not cook pasta until I know I'm 10 minutes away from serving (unless the pasta is being baked after being cooked). I keep the water on a soft boil and when the sauce is ready and the diners are ready, I crank up the heat to full, add the salt and pasta, cook until slightly firmer than al dente, drain and toss with sauce immediately. I don't rinse or toss in oil.
I like to let the pasta cook in the sauce briefly (a minute or so) as it allows the pasta to absorb some of the flavors from the sauce, which is why I take it out before it's al dente. When the pasta is my preferred doneness, I plate and serve.
Getting the timing right can take a bit of work but if you use the same brand of pasta every time, you can learn how long each shape/thickness takes and you know when to start it. Most of the time, your sauce is going to be more stable than the pasta, so if the sauce has to simmer for 5-10 minutes while the pasta cooks, it's generally not an issue. Depending on the sauce, you can usually add a couple tablespoons of pasta water if it starts to get too thick.