Oh yeah, because random guy on YouTube always knows better than the engineers who built the bike, right?
Jokes aside, upping the fork oil to 180cc will stiffen things up a bit, quicker rebound, less dive which some riders actually like if they're riding harder or carrying extra weight but it'll also make the forks feel harsher over bumps if you're not careful. If you're happy with how the bike rides now, I'd stick with the manual. If it feels too soft, then sure, a little experiment never hurt... just be ready to regret it if your teeth start chattering on rough roads hehe