@Tanuj A nice approach for this is
add a Python Hook event to the Customer based on “before_insert”, and the function will be this.
def before_insert_customer(doc, method=None):
if doc.lead_name:
for contact in frappe.get_all("Contact", {"lead": doc.lead_name}):
frappe.db.set_value("Contact", contact["name"], "lead", self.lead_name)
Every time that you convert a lead to a customer it will track the contacts.
Do you can replace the event to “on_update” for every time too.