Like the title said, there's a message cannot reach source, i think it's related to range between two chest.
So what is the limit, is there a way to configure/increase the chest target and source range?

The reach is related to your players reach distance. That means, you can transfer items roughly 2x your reach distance by standing in the midpoint between chests. That's how it works when you use your inventory in vanilla.

As it's based on your player's reach distance, any mod that adjusts your reach distance, will also adjust the reach distance of this mod.