bios – Can you switch BIOSes while the system is powered on/running?

I have the MSI X79A-GD65 (8D) motherboard. It has two BIOSes – BIOS A and BIOS B and a BIOS Switch.
BIOS A got corrupted somehow due to failed BIOS update going from v1.8 to v4.8. Now I am using BIOS B (v1.8).

The version 1.8 BIOS update is updated through MS-DOS boot mode
The version 4.8 BIOS update is done through running the windows executable from a USB flash drive. This BIOS update will update both BIOS and the “Intel ME Firmware”. Does the intel ME firmware also reside on the BIOS?

However I tried the instructions in this video: https://www.youtube.com/watch?v=66zSBpkvxEU
It worked, BIOS A’s flash got rewritten to v1.8, however I tried booting the system with BIOS A but it only turned itself on and off.

I am wondering if it is possible to update BIOS A again while booted into windows in BIOS B. Someone mentioned in a comment in that youtube video that the method works. I will flip the BIOS Switch from BIOS B to BIOS A while I am logged into Windows and then run the executable from the USB flash drive. If I do this, BIOS B should remain unaffected and it will only affect BIOS A?