Directly managed with an installed BESClient, no this is not likely as these types of network devices typically implement a highly custom/limited Linux kernel and only the dependencies specific to the manufacturer. So deploying the CentOS/RHEL or Debian/Ubuntu or other BESClient variant isn’t an option.
That said, you could log an BigFix Idea for Infiniband products. I would also recommend keeping an eye on the new BigFix Ecosystem portal for existing and upcoming integrations and partnerships.
Alternatively, if SSH is enabled on your Infiniband products you could potentially managed them via another Linux device that does have a native BESClient installed/running. For example, a dedicated Debian/Ubuntu server could contain Bash scripts for connecting to the SSH/SCP services on an non-managed switch using shared certs to upload files and execute commands. While not ideal from a reporting standpoint, it does allow for secure remote delivery and management.
I hope the above is helpful.