Yes. It's the crockpot of pasta dishes. It creates a sad mushy mush pot. What I would do instead is cook the pasta as normal. As soon as you strain the pasta, add everything else to the pot, then add the (still steamy) pasta back in. I'd skip the onions. The pasta will be hot enough to warm up the other ingredients and cook the garlic a bit and it'll be much tastier. You could add some lemon zest for good measure. Or, shallots if you want something oniony (but imo it's a weird addition).
