Does a confirmed Yamaha rider now work for Kawasaki?
MX has switched to 4 strokes for tractibility, comfort, torque, low end, easy good starts, and mild strong power with less shifting and clutch work.
2 strokes are more touchy, quicker revving, less inertia to slow down, and lighter in weight ....barely.
To me, a small weak guy, an Open class fourstroke would have more than enough power, easier to ride fast, slow down, and only suffer in slow tight turns.
I always thought a CR-500 had too MUCH power, and I never lost a holeshot to CR-500's of Paul and Dave Bostrom (top VetPro riders in my day) using my KX-420's or RM-500's.