Deducting debts when calculating zakaat

I am trying to understand a masala. For example:

Zaid takes a loan of $5,000 from his brother, and his brother tells him to pay $200/month, but Zaid doesn't pay every single month, but on and off. Would it be necessary to deduct however much money Zaid owes his brother of that loan when calculating Zakat or Zaid will not deduct anything because his brother is not asking for the money?

At the same time, Zaid's brother did not verbally mention to him that he has pardoned the debt. Would qiyas—here— be made on مهر مؤجل, in terms of it not being deducted because of عدم المطالبة عادة?