322. Collateral benefits.

There is no objection to a stipulation that a mortgagee is to have a collateral advantage1 provided that:

  1.  

    (1)     it is not unfair and unconscionable2;

  2.  

    (2)     it is not in the nature of a penalty clogging the equity of redemption3;

  3.  

    (3)     it is not inconsistent with or repugnant to the right to redeem4; and

  4.  

    (4)     it is not an unreasonable restraint of trade5.

So long as these requirements are met, there is no objection to a collateral benefit continuing after redemption, and no rule which permits the mortgagor to redeem merely on payment of principal, interest and costs regardless of