I think the point when racing is that you should either be 100% on the gas, or 100% on the brakes, and anything in between is slow.
Coming down the box one cog at a time, rev matching as you go is incredibly slow, albeit far nicer on your engine! On the track, that's not an issue, on the road it is of course.
In my early racing days I lost count, came down to first and locked up the back wheel dumping myself on the deck! Lesson learned - know which gear you're in!
Back when I was good (ha!), I would weight shift to take the braking force on my inner thigh not through my arms, then brake like hell whilst going down the box. At tip in, smoothly release the brake as you feed in the clutch whilst opening the throttle. I paid for an afternoon of one-to-one instruction and cut 8 seconds a lap off my times, but more importantly felt a damn sight more confident and in control.
If you are using your arms to brace your body weight whilst braking, then you're blocking the steering from doing what it needs to do, and preventing your arms from making any line adjustments you need. If you can't steer whilst braking then you're fecked if someone cuts across your line!
I also learned to rest my forearm on the tank when proper cranked over, as it gave some reference point and a bit of steering damper effect. That and a knee on the deck make things feel very stable when the fairing is scraping!
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