does a motherboard only work with a certain bios. for example if you had an oem mobo, does that make it impossible to install a different bios to unlock all pc features? (bios doesnt allow you to OC, can you install a different bios to enable OC)
I would say it's very risky to try and flash an unlocked BIOS to this OEM motherboard. There are too many variations of that motherboard, some with exactly the same motherboard model number but with different audio chips, different network host controller chips, etc.
It is highly unlikely that another BIOS will work in your motherboard. If the boards are very similar (same chipset) then it may partially work but you may find that some devices such as sound, networking, video, do not work.