It would depend on what you are trying to achieve with the value of accounts payable on the summary page. What I am suggesting will not delete over payments or credits, you can still drill down and see what you have overpaid.
My suggestion focuses purely on one point. You are a business owner looking at your summary page. You will want to know how much you have to pay suppliers. This will remain the same regardless of over payment to another supplier, credits etc. If you owe money to a supplier you should be able to see it on the summary page as this is the page used by business owners to see what accounts are due.
I appreciate your point about accounting equation A=L+E however people don’t use the summary page to do tax returns etc. This indicates a design flaw of the summary page as it effectively mirrors the COA. Now that I think about it, this discussion (which you yourself participated in) was covered in the post below.
I would suggest bringing back the Accounts Payable information that was lost some years ago - See post which includes an even older post I think that this would resolve this post and address my issues in the previous posts linked.