Hobby ESC’s like to FVT and other similar ESC’s only run in duty cycle mode.
This means that voltage to the motor increases and decreases with the amount of throttle applied.
The amount of current will depend on the amount of mechanical resistance or Load applied to the motor.
For example, during hard acceleration or when climbing hills.
If your ESC is only rated for a max of 35a. And 6s voltage, you will be lacking power and you will likely have trouble with overheating and will probably wind up burning the ESC down.
A 150a car ESC would be the minimum and even then you ar compromising brake quality.
This is why the majority of diy’ers are using the Vesc.
It delivers full voltage constantly and controls current proportional to the throttle with adjustable current limits.
Delivering maximum power with minimum heat.
And it offers adjustable brakes that are smooth and predictable.