If grounding HOLD# at power-on is working for people so far, that's great to hear.
You don't even *need* a BIOS-saviour like solution like this; SPI flash chips are quite easy to program in-system (if the system is designed correctly), either with the board powered on or off.
The SST datasheet implies that this is not the specified behavior, in fact my reading is that HOLD# is only sampled on SCK, and with CE# low.
HOLD# makes the flash chip not drive SO, and it would only do that on SCK with CE# selected anyway. What am I missing?
If the chipset drives HOLD# directly, though, it gets a little messier; then it may be best to put a tristate-able buffer on the SO8-clip and overdrive the mobo's SPI flash signals for the 1-2 seconds needed to rewrite the whole thing,
It's more like 10 seconds per megabyte, with a fast SPI interface.
tristating as soon as the write is finished. That starts to require a pretty fast interface, driven over a cable, and now it's a lot messier than simply hotswapping a PLCC chip!
In-circuit programming is a lot easier, heh. Many boards have a header for this btw, no clip needed. The manufacturers have similar problems during manufacturing you know :-)
Segher