This mod gives you an ability to preserve tile entity data of blocks when they are broken. For example, a chest with items -> is broken -> chest item is dropped -> all its contents are written onto dropped item; place it -> the data is written back onto the chest in the world.
The blocks are matched against whitelist of block identifiers in the config; some vanilla blocks are there by default. To add a block to whitelist, you just need to append its registry name (id).
The mod can be installed on the server without clients having it.