he doesn't need to get much better. He's already a 6'3", 65 point center who hasn't entered his prime yet. Not many of those around the league.
I think the standards a lot of posters such as yourself set are a bit ridiculous. He's not McDavid, Mathews type player and never will be. Habs aren't also paying for that level of player either. But for what he is, at his age, he's a rare specimen and he actually WANTS to play for the Habs which is the rarest of all.
Habs would be stupid not to get him, which let's be honest, is a forgone conclusion at this point. PLD will be a Hab and most likely this year, before camp starts. So accept him for what he is, not the elite, top tier talent in the NHL and sit back and enjoy. We haven't had this much depth at center for a long ass time and that's the key to building a team. For the decade long mantra of "you can't trade for a center" the refreshing nature of being able to get two in a few months, is a nice departure!