Is it permissible for an engaged couple to communicate in order to discuss how to convince their parents, who are rejecting the engagement for non-Sharia-compliant reasons, given that the parents' rejection is not final?

The suitor is a stranger to his fiancée until the marriage contract is concluded. Therefore, it is not permissible for him to be alone with her, or to look at her, or to speak with her, except in the presence of one of her family members for a legitimate purpose. If there is a need to speak, it should be through one of her mahrams or his mahrams, or in the presence of family or relatives, which is safer and further from suspicion.