FWIW
i've found several different utilities to manage the PIC firmware and the FPGA firmware for these devices. information is scattered about unfortunately.
i've compiled a binary in the past using source provided by a github repo, and that can access the `APP` portion the board, which i believe is the FPGA portion, and can dump the contents in either HEX or bin, but have been unable to dump / backup the contents on the winbond chip using such provided utility.
however my OBLS provided a means to solder a jumper header for SPI connection that allows me to connect jumper wires, thus i was able to use flashrom in conjunction with a bus pirate i have to dump the current contents of the winbond chip on the OBLS, i did not have to provide any power to the OBLS as the bus pirate can supply 3.3V to power the winbond chip to access its contents. i haven't tried to update or erase the contents of the chip using flashrom with a bus pirate, as i still need to figure out what versions i want to run and i'm still trying to gather all the necessary information for this device.
i hope some of this helps.