An
ECV, a manual chair, and a power wheelchair have sone similarities but also a bunch of differences.
My left arm is effectively immobilized as fat as reaching is concerned, so I have direct, relevant expetience.
Usually, if self propelling an unmodified wheel with one arm one would end up going in a circle with the chair because energy isnt applied equally. There are sone tools or axle modifications that can help distribute energy a bit better to avoid this. Using only one hand would also generally limit the ability to tun rapidly, at least in the direction of the immobilized arm.
You can drive an ECV with one arm, but It is really helpful to have both arms available to steer an ECV because of how the steering yoke works-you are pulling down on one side to steer the ECV in one direction and pulling down (or pushing up) on the other side of the yoke to steer the other way.
Because you are accustomed to having only one arm, like myself It will be easier for you, but can still be a strain, especially when turning in the direction of the unused arm (pushing is harder than pulling, at least for me).
ECVs do not turn as quickly as wheelchairs. but the ridr is generally a little softer.
Power wheelchairs, which Disney does not rent onsite, but some offsite vendors do, are controlled with a joystick, not a yoke. They are not as intuitive to drive as the single stick is responsible both for acceleration and direction, but can be mounted on either arm and does not require reaching. The vendors that do rent them generally will only do so to individuals who are already familiar with the way they operate.