Is it permissible for the suitor to see his betrothed, who wears the niqab, again without the niqab, after the legitimate viewing and the acceptance of both parties?

If there is a need to repeatedly look at the fiancée, there is no harm in it, in order to ascertain desire for her. As for the limits of looking during the engagement, it is what he is permitted to look at from her body. And if the marriage contract is concluded, she becomes his wife, and it becomes permissible for him to look at her and for him to do what is permissible for a husband with his wife, while observing the condition or custom of delaying consummation.