from my understanding, the only way to select a timeslot on the calendar from a touch device is to tap and hold, I'm looking for a way to handle tap in the same way the calendar grid handles on click. I do not see a way to do this in the documentation.
The answer to my question was provided by ADyson in a comment:
If it's not documented then it's unlikely to exist. I'm not aware of anything else. The reason is probably because you can actually drag to select a larger time slot, and also tapping is probably considered like a "click" on the day, which triggers a different callback event.
I suspected that this would be the case, but I'm not super familiar with FullCalendar, so I wanted to double-check in case I was missing something.