We would always apply for Summer term during the application process. They would then take a 1 credit class Summer. My son did that and then immediately left on his mission, my next daughter did the same and then went to another University on an Athletic scholarship, left on her mission and then can back to BYU. They viewed her as a returning student.

My next daughter took the one class, then went and taught english in China. And came back to BYU. My fourth, took a class, worked a semester and left on a mission. When she came back, she could choose between BYU and Another University.

Worked great.