That's pretty good audio. i believe you when you indicate the sound wore you out. High frequency noise will do that. I wear reusable ear plugs whenever I ride. They allow me to hear unusual noise if it develops but damp the high frequency noise. It's a habit I developed while running chainsaws, splitters and skidsteer loaders, all of which do a lot of whining.
I hear a metallic whine but can't identify it. I'd check where Gryphon indicated. If you don't have a mechanic's stethoscope, take a screwdriver and place its blade on timing chain cover down toward the rotor end and its handle to your ear and get somebody to rev the engine. Although this noise is heard under load, you might hear the chain rubbing on the rotor seal bore, which would indicate a worn timing chain tensioner and maybe a worn chain, too. You could remove the cover then look at the rotor seal bore on its reverse side for dings or gouges.
Any leaks at the combo pump weep hole? Take a listen there too.
Your moto had 50,000 miles on it in 2017. You adjusted the valves back then. How many miles does it have on it now? Others here will have more observations to add.
