Thanks dhunink. I was hoping to resolve sharing the w3tc configuration, using s3fs to mount an AWS S3 bucket (it's how I already share media uploads across servers).
I setup a symbolic link in-place of the existing master.php config file, that points to the file within the s3 bucket. This doesn't seem to work, as w3tc blows aways the file and re-writes the entire config file.
Any suggestions for sharing w3tc cache settings across servers?