First change the PCV valve if it has not been done recently. You could also try the ATS Carbon Clean product that Scotty has talked about if you can find it in stock anywhere. (It has been unavailable recently due to supply chain problems.) Other that, just add oil as needed.

Up to one quart every 1000 miles is considered "normal" when it comes to new car warranties. It is best to stay away from dealers for anything other than warranty service.

Excessive oil consumption is a known problem with Toyota 2AZ-FE 2.4 engines, but supposedly limited to 2007-2011 models.

For the benefit of those of us playing along at home your Toyota service dept is saying that these holes (under the oil ring) are clogged up.

And there's no way they could have physically examined this so they're going by their experience on engine tear downs with this oil burning issue.

So how can you unclog those holes? @chucktobias suggests trying the ATS Carbon Clean product which Scotty reviewed and it sure couldn't hurt anything to try it.

The truth is, your engine can last another 100,000 miles with these holes clogged up as long as you keep an eye on the dipstick. (you may have to change the spark plugs more often)

But your catalytic converter won't like it. They don't like oil. Oil coats the metals used in the cat and when that happens the cat can't work.

Cats are expensive and with an engine burning oil the replacement cat is going to foul with oil just like the original cat did.

Maybe occasionally do the finger test.

Stick your finger in the tailpipe. Is it oily (wet & black)? If so you'll have to decide if you want to keep the car knowing that the catalytic converter failure is imminent.

I agree with @chucktobias.

I'm curious how often have you changed the oil?

What do you mean by "at Toyota?"  You mean a dealership?  Did you ever check their work after it was done? 

I change the oil every 5,000 at Toyota