Installing jumper headers on the P3 jumper block and cutting some traces on the back side (P3/C pins 2-3 and P3/D pins 2-3 are hardwired, see attached photo) appears to make this board conformant to the Octek MicroEGA P3 jumper block settings.
P5 jumper selects the EPROM type: short 1-2 for a 27128 chip, short 2-3 for a 27256 chip. The actual BIOS code is just 16K, so those are attached as "trimmed" v2.3 and v2.4 16K BIOSes to burn on a 27128 chip.
To see Hercules Graphics you need a TTL monochrome monitor - so no full emulation of graphics modes