It says in BWG that a Beginner’s Luck test that is difficult or challenging for the base stat is recorded as a test for advancing the stat, not the skill that you’re trying to open. But what if you’ve already logged all the tests of that type that you need for the stat? I.e. you doing a Ob 3 test with a B3 Agility, which is difficult, but you already have the 2 tests that are needed to advance your Agility. Can you count that test towards the skill instead?
No. You cannot convert tests. If you’re already filled up that sort of test then you don’t learn anything this time.