The BIOS option has nothing to do with the Intel SSD Toolbox tool's capability. The BIOS option when enabled issues an ATA command to the drive whch returns the overall SMART health status during system boot (prior to the OS loading). If the overall health check is failing, the system will pause/stall and inform you of such. That's all the BIOS option does.
If Check SMART Attributes is greyed out, something else is going on with your drive that is extremely unpleasant. Can you please download and install HD Tune Pro (trial version is fine) and provide a screen shot of the Health tab for your drive? Thanks.