Updating Bios automated accross network
You could try using the 'Dell Updates' section under security, I never personal tried patching the bios with it yet, but it's there.
Just create a smart label on Home > Label Management > Smart Label > Choose Action > New > Dell Update Smart Label
Filter by "'Package Type' is 'bios'" (I'd also, for caution, filter for specific devices in the 'Name" field)
And use that label to create a Dell Update Patch Schedule.
Give it a shot and tell me how it went!