I have used 20W50 in my previous corolla for years and it was also the same engine (2N-ZFE). It was hardly 40 K when I started pouring Petromin 20w50 and it worked flawlessly even in subzero temps.
There was not a slightest decrease in engine performance and when I sold it after 10 years at 134,000 it still looked, sounded and drove like a new car.
So take my words it will not harm engine in any way.