yes, that's the gnu cash implementation (also used by formance for example) - I don't love it tbh, yes you can add multiple postings under a single transaction, but.. if you look at one of those postings, or just the transaction in general you don't directly know which posting originates from what account, you have to sorta map it based on amounts
Jumping-in as I happen to know formance very well; I'm 100% agreeing with the need to know what posting originates from what account, which is why formance transaction format is essentially a container for postings, which themselves are a quantified, directed relation between exactly 2 accounts. So a transaction can indeed impact N >= 2 accounts, but a posting within a transaction will always relate exactly 2 accounts.