Is it necessary to wait until the erection subsides or the madhy (pre-seminal fluid) exits before performing ablution (wudu’), or can one perform ablution immediately with intermittent madhy leakage?

If seminal fluid (madhi) exits intermittently, and the worshiper finds enough time to perform the prayer with proper purification, then he must wait for this time to pray therein without anything exiting. Performing the prayer with certain purification takes precedence over congregational prayer, and this is not considered سلس ( سلس is a medical condition of continuous involuntary discharge).