again, idk if its been posted but here it is
1) go in the alliance flag room
2) stand on the cap point, and look to the left corner (of the cap point nook)
3) run and jump into the corner- you should be partly in midair (if not, try again)
4) jump and press w- you should be a little higher up
5) repeat- you can get high enough so melee cannot reach you
also good for healers on the flag carrier when trying to get their flag back