You should be able to start now...but...
You may want to check with your local Toyota dealer to see if RP voids the warranty or not. If something happens to the engine, you can bet RP won't pay the tab, but your local Toyota dealer may realize you weren't using recommended Toyota (Mobile) oil. If your local Toyota dealer says go ahead, get it in writing. You can also email Toyota and see what they say. It's very odd RP says to wait until after the mfg. warranty is up. What if one bought the 7/100,000 warranty?
I've used Mobile 1 Synthetic in my F150 and changed oil every 10,000 miles. I put about 18,000 miles a year on my truck, and it's all city driving - stop light to light. I start the truck up probably 6+ times a day as well - very hard on an engine.
The truck has 140,000 miles on it and purrs like a kitten. 5,000 IMHO is overkill for a full syn oil, especially if you don't drive like I do.
Using RP would seem like a waste of money, seeing how every oil change could run you $75 unless you do it yourself. I think you can buy a case on ebay for around $77 shipped, but our trucks could take 7+ quarts per change.
On tip - don't ever change oil types once you start. Stick with syn after the first change and don't go back to standard.