If you feel the temptation to collect chests during the execution of missions, you are not alone.
However, this can be a rather tedious and even difficult task, given the complexity of Crisis Core and a huge number of available missions.
But do you really need to collect all the chests in the game?

are chests part of the percentage of completion in the FF7 Crisis Core?

Although there are certain missions, for example, in Gonna, where the discovery of a certain number of chests gives you trophy, not every mission requires the opening of 3/3 of treasures.
In fact, there are no side missions that need every open chest.

Mission

So, if it’s hard for you to find them all, this is not a problem.
There is a hidden achievement of the Treasures of Manor that you can get by collecting all the treasures on the ground before you save the mother of Angela.
However, chests are still not included in this list.

should I open each chest in Crisis Core?

Although you will not receive trophies for this, we found that the opening of each chest with treasures in the mission can only help you.

Some of them will contain useless objects, such as potions, but others will contain useful, such as matter, elixirs and even accessories.
With Fusion In the game, this second moment is especially important to determine how much Oak can be equipped for certain missions.
To get additional assistance on Final Fantasy VII: Crisis Core Reunion, read the sections How to unlock additional slots for accessories in Crisis Core and How to increase the level of Buster Sword in Crisis Core here, in the guidance on the game for professionals.