Thanks for your response.
One of the chief reasons I purchased this particular model was precisely because it was equipped with a second hard drive bay and my assumption that I would have the option of booting from a 2nd installed HDD/SSD.
What I find somewhat strange is the similar inability to boot from a cloned USBEHD even though the BIOS Boot Options Menu lists a "USB Hard Drive" as a bootable device. As I indicated in my post I've been able to routinely boot to a cloned USBEHD in 2 previous HP laptops.