Break in oil change?

If Toyota isn't the exceptional brand, who is?

I'll let the resale value do the talking on Toyota's quality, or lack thereof. Last two for me returned 95% of the MSRP when sold (to dealers).

 

IMHO; Don't tell your dealership that your running 0W20 - Dealership can use that as a basis to VOID your warranty. You don't want that fight.
You've got at plug-in and running 80% in EV mode - so your only working the ICE 20% of the time. IMHO; I would do oil changes every 5K mile NOT every 6 months. That would be every-time the maintenance lamp turns on; that's assuming that the software is still on a 5K miles trigger base, like the gen4. As long as your using good quality, full synthetic oil, you should be good. If the oil turns really dark brown to black, then you need to increase the intervals, but I'm pretty sure your only going to be a light amber at 5K mile intervals. I do 10K changes on my gen4 and running the same EV-HV ratios as you are and my oil gets to be a dark amber or very light brown. I need to use a tissue paper to find the oil level on the dip stick for about a month, after my oil changes. I've calculated that I have around 7.5K max actual ICE miles on the clock. When I do run the ICE, I make sure it's running for at least 15 minutes solid - meaning engine gets up to temperature and then some to burn-out evaporate any moisture and fuel accumulated in the oil.

It's a different story for a non-plug-in.......

Hope this helps

PS: don't forget to change your ATF around 50K miles - that's turning all the time, no matter which mode your in...... I believe your transmission takes the newer specific ATF formulation as opposed to my generic ATF-WS.

Good Luck...