If you two are the only applicants in the entire MX group, you can reach a universal time share agreement either before or during the 90-day window. REC recommends you execute the agreement prior the 90-day window if you are in that exact situation.
Note that 5-point and 4-point applicants cannot aggregate their points together against other applicants in the MX group. Applicants with different scores may not enter into a partial settlement agreement during the 90-day window.
LPFM during the filing window