Child table load time

Hi everyone-
We have a custom doctype where you enter a date and the custom child table fetches all purchase invoices due by that date. The child table is taking a very long time to load when we set it to 500 or 200. Ideally, it would be 500 for our use case. When set to 200, browser says “this webpage is taking a long time to load” and it takes about 2-4 minutes to complete. When 500, it says that about 5 times and takes nearly 8-10 minutes to load.

Any ideas on how to speed it up or if we should be using something other than a child table?

filters: {

                 due_date: ["<",],
                     is_paid: ["=", "0"],
                     outstanding_amount: [">", "0"],
                limit_page_length: 200