great, maybe you sniffed it out. you've never said it overheats, no bubbles, and it's passing the pressurized coolant test which is the best one for this engine and your scenario. so there's no immediate headgasket indicators, it's just not something to forget either.
it's common for initial EJ25D headgasket issues to pass nearly any test. cooling system pressure test is the best and the electronic $$$$$ hydrocarbon sniffers (not the chemical test styles) are great but not widely available.
compression test and milk and oil mixing or coming out the tail pipe are essentially pointless and a waste of time on that engine. they never really do that or if they do it's already so obvious the test isn't needed.