I just had another idea. If this Glow Plug module works the way I think it does, what do you guys think about a module that has a setting on it for 5,7, & 11 Volt Glow Plugs? No need for a computer reflash as the setting would be done at the module, NOT in the computer.
It wouldn't matter what the computer is flashed at as the module would have the final say on what the voltage would be to the Glow Plugs. It would still retain the ability to "Rat Out" a bad Glow Plug by the CEL on the computer.
Now all you have to do is figure out what metal-sheethed or ceramic ones you want and you are done.

I do need an old Glow Plug module/realay if anybody has one that they want to donate or sell for a good price. (I need to do the final R&D).

So what do you guys think?

That's a great idea and hope you can make it work. Would be nice to have option to bump up my 7v ceramics to 8v line voltage when they start to go.

I was thinking of modifying the existing circuit. Extending the pulse length for the 7 volt system.
Just a thought; a hundred others things to do first though.

Sounds like a good idea. I hope you make it work.
Reprogramming the ecu would be the easiest way (if we knew how!).