*Intermission 2*
The answer to that last question is:
Not nearly as many as has been happening here. 2-3 times a day at most.
So what's really happening here?
The only parameters Jeff set was the 24 hour option, and to be a full-grown jackass. The chronivac sets up a bunch of other parameters automatically if they remain untouched.
It is the assumption of the makers of the Chronivac that a person who selects him/herself to be transformed would like a pleasurable experience. If the mind-altering option is not touched, it will never assume to alter the user's own mind automatically except through special circumstances. So it cannot FORCE a user to find pleasure once they are transformed. But it could still find ways to manipulate a pleasureable experience within the confines of it's hard code.
The makers also assume that the user would like the full experienced of whatever he or she turned themselves into.
Jeff's chronivac "chose" him to be a middle-aged, horny old fat jackass. This was NOT to Jeff's liking, obviously. But if the Chronivac cannot alter the mind of the user directly, and it's instructed to assume the user should have a pleasureable experience, the chronivac's programming "decided" to pump up Jeff's donkey's body testerone levels to above average for a large jack like him.
Meanwhile, the blood supplying Jeff's human brain is of donkey origin. And with it, increased deposit of donkey-sized testosterone.
The first couple of ejaculations horrified Jeff. And because he derived no actual pleasure from his dirty deed, the chronivac would "super charge" his body's production of more donkey sperm.
The increased hormone levels produced by his body, would make him horny once again. And again, he would spill his seed. And again, he would derive no pleasure from the experience. And again, the chronivac would just "refill" his balls.
Slowly, with each passing male orgasm, Jeff began to acclimate to his condition and started becoming less resistent and more receptive of the acts until he satisfactorily derives pleasure from his experience.
Now, if Jeff never derives any pleasure before the 24 hour timer is over, then the timer itself would overide all other parameters and revert him back to his human self no matter what. It was a failsafe. The timer is the most important parameter on this infernal machine.
There are unforeseen consequences that even the makers of the Chronivac never took into consideration, and those consequences will be revealed in the future. But for now, Jeff the donkey is having his donkey balls be refilled yet again. Those balls are beginning to churn, and he can begin to feel it deep within.