To prevent Invoice Splitting-Large numbers

We have large amount of billing documents for smll value transactions.

I fully understand the criteria for invoice splitting. In our system we have service orders so no delivery. Billing is order related.

The problem is like this which need solution.

The requirement is to prevent invoices from splitting based on the large amount of billing documents only. That is all conditions for invoice split have passed at that time and invoice split was not required. It will yet happen due to the limit of 10K billing documents on one invoice list.Please note that we have pricing procedure non sap standard & around 18 condition type is User Exits. So processing time is more. I am afraid that if we go for preventing invoice split, the processing time would increase. As we have monthly around 50K billing documents.

I need solution

1) How to prevent splitting of invoices & make them into single billing document

2) Can we handle large amount of invoices like 60K per month?

3) What is best solution.

Appreciate your valued feed back. THANKS.