I have worked with Netskope team for Netskope silent deployment on Big Sur OS using BigFix MDM. I have created system extension policy and they had given proxy pop allow policy file. With the use of these we are able to deploy netskope agent on Big Sur silently without any pop-up. Soon they will be releasing document in their site that how we can do it using BigFix MDM.
Unfortunately after this much time that Big Sur has been released, BigFix hasn’t integrated system extension feature which is a major pain and lot of efforts needed for application deployment.