As one myself zealous to place the Gospels in their historical (Jewish) context, there is a legit critique to not import 4th century rabbinic stuff into the text. How sure are we that afikoman was practiced in Jesus' day, for instance? I don't know. Any resources from readers are welcome.
Assuming conservatively that it was NOT, it's still great to be all things to all people, especially to Jews today. Communicate the gospel to them with what they already know, especially to the Jews (Romans 1:16). Some think it is all a fad, or Judaizing. And I know much of it IS based on identifying with Israel, or having some new thing tickle our fancy.
Let's be careful not to assert things tacitly that we're not sure about. Better to teach on it that the Jews today have this practice, and isn't it interesting that what Jesus did fits it. Rather than assuming (thus asserting) that Jesus did what the Jews do today, or did in the 4-5th century.