That kit you linked to increases the volume of oil flowing to the cylinder heads. Since it doesn’t increase the total volume of oil being pumped, it reduces the volume of oil flowing to the other parts of the engine, notably the crankshaft.
When Honda designed the engine, they sized the oil passages to get the percentage of oil they wanted to the various parts. If it turns out that they made a mistake in dividing up the oil flow, then changing the percentages with aftermarket plumbing could increase the overall service life of the engine. If they didn’t make a mistake in how they divided up the oil flow, then changing those percentages would make the engine less reliable.
In any case, if you increase the oil flow to the heads, you need to be sure the drain passages are big enough that oil doesn’t start collecting under the valve covers during extended high rpm driving. If the oil doesn’t make it back down to the pan fast enough, the oil pump might start sucking air.
Those are the potential benefits and risks I see. I can’t remember anyone who has rebuilt their engine posting that the cylinder heads look like they aren’t getting enough oil. However, a shop that has rebuilt many NSX engines such as Driving Ambition or Science of Speed could tell you first hand whether it looks like Honda undersized the cross section of the oil passages to the cylinder heads.
