mine makes that noise sometimes too. it goes away most the time, i always though it was a little bit of chain rattle before thinking rod knock. beside the point, if it was rod knock my oil filter would've been full of metal and its not. I agree it is weird but I've never stressed out over it too much. chain still is tight and engine has ran great despite the noise coming and going. noticed it years ago so if something bad was going to happen it probably already would've. i just keep the same routine, let her idle down, make sure oil is full via IID tool (before cold start), wait for the engine to warm up to 170-180 before going over 3k rpms, and 5k oil interval changes. I'm reasonably nice to this engine but the occasional freeway acceleration is fun with the muffler delete. that being said, oil needs to be full and warm before any of that happens. i think your fine, these engines are weird, don't let the constant anxiety overshadow the greatness of ownership, just be smart with how you treat the engine.
Edit: Another side note, the noise never increased when engine speed increased so I never really stressed.