Revenue Budget - add amount to the revenue budget

Revenue Budget - add amount to the revenue budget

I just realized that only the Revenue Budget gets to sync over to Zoho Invoice, and I was informed if I have already sent out invoices then I can't add/add additional amount to the Revenue Budget, UNLESS I delete the invoices first, add the amount to Revenue Budget THEN re-create the already sent/paid invoices.  Can you please make an easier way to do that?  Thank you.