Miller is by far more valuable to the team. He has top 10 scoring finishes on both a low and high scoring team, with huge discrepancies in linemate quality. EP is much more dependent on others, and has been wildly inconsistent.
Canucks best seasons, are with JT as the teams best forward. If it's Boeser or EP leading the way, they are in lotto contention. They won their division with EP being a non factor for most of the season.
EP likely gets the better return, due to age, and not having an NMC in place, plus gives more options cap wise.