Using a BuckBoost to go from 380V to 460V

I’ve got these machines with two Servo Motors on them, 3KW, and 1KW, with Kinetix controllers.
They run here in the USA at 460V 60HZ
I shipped them to China where the voltage is 380V 50KHZ
Everything works great, the Kinetix controller don't seem to mind the lower voltage. Of course I had to change the Xfmr for the control voltage.

I have noticed that the reaction times of the motors are not as good there.
When I try and Accelerate, and Decelerate. I’m not getting as good of performance.
It’s hard to Quantify.

What I am considering is putting a Buck boost in front of the Line, so that the Machine gets 460V @ 50Hz.
I know I'll have to change back the control circuit transformers.

Anybody done anything like this before?
Thanks

I would run this by your transformer rep first and get his recommendation.

in regards to the drives, is there a setting where you can state the operating frequency and change it to 50 hz?

james