Niche is definitely good enough to get a quality cup, and sounds like you’ve got a great setup for what you’re brewing. If you do ever try a cone, you can still get some great results with a $9 V60 and a classic kettie spout, too, especially if you pulse your pours.
And yeah, like you say, a Brazil is almost always going to be chocolate forward, so that makes sense. They are also often roasted medium to city/dark, so I wouldn’t typically recommend easing off the water temp, but a few degrees can make a bigger difference with darker roasts, in case it is one. But it does sound like you’ll find what you’re looking for more with a higher elevation and lighter roast. I’m personally a huge fan of Dune coffees.
Hope grinding finer is great! And if not, you’re one step further along in the process of elimination haha.