Guidelines around when to use separate configuration and content databases

I am new to Nintex and while reading the installation guide I noticed that multiple databases could be used to store Nintex workflows. However, I didn't see was any clear guidance around when to use separate configuration and content databases or when to use multiple content databases?  Is there any information out there that I can reference to ensure I set up my environment correctly? Are there thresholds or limitations of the tool that I need to be aware of?

Thanks,

JB