They're basically going through puberty when they're on HRT
So think of the energy levels of a teenage boy and you're basically spot on
The way my transmasc friend described it I basically went "Yeah that sounds about right: infinite energy, an infinite appetite, and a level of confidence that's suddenly staggering"
A chaser fetishize and go after trans people in the same way people fetishize asians, latinx, black people, ect.
It's not wrong to have a preference for trans people, it is wrong to reduce them to a sex object for your pleasure. That's what a chaser is.