Hat in the oil... The only thing I may do is add some Duralube at the next change. I've had good experience with that product over the past 20 years or so getting mileage out of engines that historically did not perform so well for others, even when mistreated (dollar value unknown). Although the test case is "unique" here, often the comment section is full of user data. Several of the positive reviews I can personally attest to. More important with our very infrequent oil changes is the use of a very good oil filter brand that has good seals so they do not leak over the average one year service cycle.
When I bought the Clarity I drove it primarily in HV Charge mode, often very conservatively for the first 1000 miles (unlike my usual lead foot) to attempt to break in the ICE as best as possible (not going to debate the need for break-in of a generator that is entirely computer controlled here, it is a habit from being a pilot). Now that I have about 100 hours on the ICE I am going to treat it like all my other hydrocarbon burning friends and put SR3 in it. Yes, I am fully aware of the FTC suite and all the controversy. Just doing what has worked for me. Even my Honda dealership sells Z-max as a "add on" for their OEM oil changes. As long as you use a minimum spec oil per the manufacturer your warranty is secure. Hat out of oil, now placed carefully in oil recycling tray to drip dry...
Cheers,
Cash