Try using Box Drive to preview them on your computer. Using Box Drive will allow you to make your edits on your computer and Box Drive will sync them back up to your account. This is what we use when we need to preview and work on BRAW files.

Hi Robin, 

Welcome to Box Community and glad to help! 

As of this message, these are the file types supported in Box content preview.

Let us know in this forum if you have questions. 

Thanks for posting!