Unfortunately I haven't had much time mess with this lately, but I do seem to be struggling with a stability issue since the mod.
I can let quake 2 run for hours without a hitch, but as soon as I start navigating around Windows 98 the machine will just randomly reboot. Never a blue screen or lockup, it simply acts like someone pressed the reset button. I don't know if it's related to the mod, or if there's some other issue at play. I sort of doubt it's the mod because the problem seems to occur more often once the system has been on a while...
There's also been some "oddness" going on with Vcore jumper settings. Even though I'm using a K6-2+ with a nominal Vcore requirement of 2.0v, I've discovered that I need to set the jumper position to 2.1v to get the board to post and boot. And the hardware monitoring menu in the BIOS shows 2.0 volts. If I set the voltage to 2.2 volts, the monitoring shows 2.1 and the system becomes barely stable enough to even browse around Windows. I suspect either the power supply I'm testing with to be at fault, or perhaps some caps in CPU VRM section of the motherboard are allowing too much ripple. They look OK and are a mix of Rubicon and Sanyo but you never know. When I received the board the area surrounding the CPU socket was caked with dust from the CPU fan, so I suspect it's got tons of hours on it...
Once I have some free time I'll dig into this a little deeper, because as long as the VRM behaves strangely it's impossible to know for sure if the mod is responsible for any stability issues or not.