900 Fuel And Exhaust/induction Question

Hi all,
I have a 2023 900 Scrambler and I love it. I was out the other day with my mates and we stopped for fuel, some put in e10 and others put in e5, they all ride Kawasaki or BMW. This got me thinking I’ve always used e10 but what does the 900 like, are there any gains using e5 in it? After all it’s a lot more expensive, I’ve tried it in cars and bikes before with no real improvement.
I like both the look and the sound of the standard exhaust but I wouldn’t mind May be just a little more volume and a few pops and bangs any advice please? Which brings me on to induction is it worth fitting a K&N air filter or something similar? As that would also I assume give me more induction noise?
The problem is unless someone has actually tried these things on the 900 engine I have no idea what the outcome is as you can do these things sometimes and actually make it worse.
Thanks in advance.