Making scheduled updates to customers

Some of our customers are credit unions and we vary pricing based on how many members they have.

I want to iterate through every customer that is in the credit union classification and check their membership count on a regular basis. I already have a module for some specific code we use, so I’m guessing the right way is to add it to that module.

Is the best practice to do this add a python function to an add on and use the scheduler?

Then use something like frappe.get_list("Customer", filters={'customer_group': 'Credit Union'}) and iterate over the returned list and doc.insert() each one?