well, that’s a classic worst-case scenario. Frankly, the risk is that the whole G/L and VAT can lose its consistency. On the other hand, if your NAV partner knows what they’re doing and put the deleted records into archive tables, this can solve problems… an unmodified CU 12 will not allow inconsistent postings. By deleting entries after posting, the consistency is no longer guaranteed… aside from the fact that you will have missing entry nos, which auditors will find and ask you where they’re gone.
In short: When done in the wrong way, your whole G/L will become invalid. The right way should be approved by an auditor.