'92 SVX burning out ignition modules?

[jlaguardia]

I've had a '92 SVX for 8 years or so and fixed a bunch of relatively simple issues over the years, but now I have a bug that I can't find an explanation for. I searched this forum but couldn't find this exact issue. What happens is the car begins to misfire at cruising RPMs (and higher) - it will idle OK and I can usually limp it home. If I turn it off and try to restart it, it will crank but not restart. I had a similar problem once with another car, and took a guess and replaced the ignition module that's bolted to the firewall with a used one on eBAY, and that seemed to fix it - for a while. After a few drives, same thing happened again with the second module. I looked around and found some forums (not SVX) saying that ignition modules in cars of this era can be damaged by bad coils somehow "feeding back" into them. So I bought all-new coils ($$$), and found another used ignition module, and again everything seemed fine for a couple of drives. Then it happened again - rough at high RPMs, limped it home, and now crank with no start. Has this "burning out" of ignition modules happened to anyone else?