1ppm/1k miles is a very good wear rate.
Changing to a different lube isn't likely to alter the wear rate appreciably, despite all the rhetoric.
Shortening the OCI isn't likely to improve the wear rate either.
As for the varnish fears, I'm going to say something that will make some members just cringe ...
Varnish is nothing to worry about. "Varnish" is just a slight tinge or pigment change in color on metal surfaces, and does not indicate anything dangerous is happening. It's not uncommon in many engines to see varnish, and they can run just fine with that varnish being there for hundreds of thousands of miles. Varnish is WAY overblown and misunderstood. I've had several vehicles with varnish on the surfaces of the metals, and those engines ran well past 200k miles, had no compression issues, had great UOAs, and had no adverse performance problems.
Never confuse varnish with sludge. Sludge is a serious issue where insolubles and oxidation byproducts and not held in suspension in the lube and allows deposits (especially in localized hot-spots) to continue a formation which can affect lubrication and oil return. Sludge is a problem with much older API spec'd lubes from decades ago; they were not made with longer OCIs in mind. Further, engines that have some poorly designed or selected criteria will be prone to sludge regardless what oil is used. Most engines, however, are not "sludger" engines. Of note, the older Saturn SL2 engines, some Porsche engines, and some Toyota engines all had sludge issues due to various design/component criteria. Just know that "sludger" engines are actually not common.
Further, total neglect can induce sludge issues, but it's not fair to blame an oil for a complete lack of oil changes. I knew a guy I worked with at Ford back in the day; he never changed oil - he only changed oil filters every 5k miles, and then topped off. Oddly, it didn't seem to alter the way his old 4.0L Cologne ran in his Aerostar, and it had over 150k miles on it..... but that's not an advisable way to treat an engine.
To the best of my knowledge, there's no proof that the 5.0L Coy motors are sludge-prone engines.