Hi FJ12Ryder.
I'm with you on this, and at the risk of also stepping back into the "shithole", just wanted to update you on the Flapper Removal from my 8th gen.
My reasons for removing the system was based on Honda's removal of the system from the 2017 model, I was keen to simply remove some clutter from under the tank Provided I didn't induce any detrimental effect on performance, fuelling or fuel economy, have had an open mind about this systems pros and cons for ages - technical and personnel opinions abound with the system! This is a subject that has been thrashed to death
I can only say that my bike is SUBJECTIVELY as good if not better without it. I can definetly (at least) confirm after approx. 10,000kms without it that my fuel economy is as good if not better.
I personally believe that the state of your air filter (cleanliness) will have greater effect on performance than what the Variable Intake System can offer - Subjectively speaking. It's no surprise to me that Honda have removed it. YMMV!
Now - also stepping out of the "shithole"!!!
Cheers.