I get it.
But I’ll play dumb.
Let’s assume that the sugya was learned through and through and the person has come to the conclusion that Rav Emden’s psak should be followed. The next theoretical issue to be resolved is “Does this psak pass the smell test? Is it reasonable in any way?”
It should be obvious to all that times change and our halachic behavior changes with it. This is why for many situations we ask shailos and don’t rely on a written opinion in a given sefer. As we know, many torah greats did not put their opinions down in writing for fear that one day circumstances would change and the psak wuld no longer be valid.
Tachlis, one must have “einav b’rosho”. Rav Yaakov Emden is worthy of following , no doubt about it. But always? Think twice.
So does one stand on solid halachic ground? Yes. But that’s not enough.