Possibly add a randomized date to new UA, in range from last fixed CVE, to browser compilation date That would avoid feature detection, but still create epochs

Possibly add a randomized date to new UA, in range from last fixed CVE, to browser compilation date That would avoid feature detection, but still create epochs to disallow insecure browsers -- For exception tracking, the best I can suggest is getting screen size + other features; then storing them, ready to pass with the exception