Theoretically, any free trade agreement would promote economic growth. How things pan out remains another issue.
It can often comes down to what does any particular country has to trade with and are there particular buyers willing to make the trade.
Issues like comparative advantages come into play, as well as balances of payments/trades.
I haven't looked into the CPTPP, so I haven't done any in depth analysis on the issue.
As each country has more than one export good to trade with, and there is strong dynamics in the commodities, currencies, and export markets, it's likely an indepth analysis is required along with some pain in the rear calculations that need a lot of data.
I am not sure if the above is a satisfactory answer, but if you want an indepth report you're better off googling for it.