Personally, at this stage of my career, I would not mentor a team if I was attending college, even if it was 2 classes a week. I would offer support on the weekend during build season ( probably manning the grill

) but would be very conservative of my time during the week. Granted, I work full-time and classes would be on a part-time basis.
Colleges and professors only care about academic performance. Thats what they are paid to do and that is also what you or your parents are paying for. Volunteering is a noble deed, but don't lose sight of the goal in front of you. FIRST doesn't offer scholarships for 'Best Mentor'.
If you are in college, keep your eye on the prize, help when you can, and look forward to the day when you can mentor yourself through the eyes of a prodigy. You will be rewarded in due time, and enjoy the experience better when you have better monetary resources available to you to make an impact.