You can put risers on just about any bike, raising the bars to a more neutral riding position... Google Heli-Bars. You can also put a "throttle tamer" on as well, to take out some of the "jerkiness" of the throttle... it changes the "switch" on/off of throttles.
Any bike can be customized anymore to fit anyone... these days.
https://www.helibars.com/
https://www.revzilla.com/motorcycle/...r-yamaha-r1-r6
I've been riding for years... ask away...