I would drive it a couple hundred miles, do a few rolling wide-open throttles to seat the rings properly and then drive it to the 5K that Toyota/Lexus recommend.
The wide-open throttles if done on a warmed up engine and while rolling will not hurt the car and actually benefit the engine to seat the rings properly.
Just drive it till 5k, nothing to worry about.
The 6.6 qt sump for a 2.5L V6 is a lot of oil, if you look at clublexus.com and the UOA people did, most synthetic can go 15k and dino is good for 7.5-10k.
I think the 5k OCI is a safety margin for fuel dilution due to the direct injection. Because of the sump size and the 5k OCI, I'm just going to run the cheapest dino I can find (i.e. free oil from rebates) and call it a day.