I have the same noise. Ish.
So far I’ve changed the oil for top spec 5-30 fully synthetic oil and changed the filter too for a genuine Honda item. The car had been serviced before I bought it from a garage but I NEVER trust that it’s been done correctly - cars love the correct oil and it’s cheap to do it - I did it myself.
I’ve also been adding an octane booster to the fuel each time it’s filled up. I used this one
https://www.halfords.com/motoring/engine-oils-and-fluids/fuel-and-oil-additives/millers-petrol-power-ecomax-500ml-166788.html as I think it’ll probably be cheaper than premium fuel and it’s easier to add this to my normal fuel than seek out decent Shell V-power or similar (I’d only use V power personally, not all high octane fuels are the same!).
I’m sure the noise has reduced somewhat with those changes but I have more planned.
I’ve just bought a full set of iridium spark plugs from sparkplugs.co.uk - cost was £48 for a set of Denso SKJ20DR-M13 plugs which are recommended by Honda (they recommend 2 types - see the screenshot I have attached from the Honda dealer service guide - but these are the cheaper ones).
I’ve also got a genuine Honda rocker cover gasket and sealant and I’m going to check the valve clearances - just got to borrow a torque wrench from a friend to to that. I’ll do that at the same time as the plugs.
I had a good look under the car but I couldn’t find any loose heatshields but when I do the plugs I’ll get better access behind the engine to check there.
Basically I’m doing what I do with any car - do a compete service and change everything that’s fairly cheap and could promote poor running or poor reliability. I don’t trust garages, not even dealers to do everything correctly. I can’t do everything mechanic wise on a car but this sort of stuff is pretty much bolt on - mostly using a Halfords advanced socket set!!
I’ll let you know how I’m getting on.