No idea if this will work, but this little gem in GCTech.TECH offers a suggestion:
//------------------------------------------------------------------------
TECH 999 ImpossibleTech
//------------------------------------------------------------------------
Name "Impossible Tech"
Model ""
Tech_Requirement "ImpossibleTech"
Research_Cost 55000
Overview "If you're seeing this it means you're looking at this tech file. Naughty naughty."
Description "This tech is impossible to research. So we use it as the requirement for one time units."
Tech_Category 4
ENDTECH
So try changing final frontier to this:
//------------------------------------------------------------------------
TECH 89 FinalFrontier
//------------------------------------------------------------------------
Name "Final Frontier"
Model ""
Tech_Requirement "999"
That may prevent you from ever being able to research it... it may also cause the game to crap out, your car to break down, your wife to leave you, the sun to implode and/or releasing an evil force called Draginol from dark stasis.
No warrenties expressed or implied. Void where prohibited. Tax not included. With approved credit check only. Employees of Stardock and thier relatives are exempt from play.
I suggest just disabling a tech victory on the begining screen when you start a new game. Then it doesn't matter if you research it the game will continue.
You can remove a Tech from the list by commenting it out, like so:
//------------------------------------------------------------------------
//TECH 999 ImpossibleTech
//------------------------------------------------------------------------
// Name "Impossible Tech"
// Model ""
// Tech_Requirement "ImpossibleTech"
// Research_Cost 55000
// Overview "If you're seeing this it means you're looking at this tech file. Naughty naughty."
// Description "This tech is impossible to research. So we use it as the requirement for one time units."
// Tech_Category 4
// ENDTECH
Best to make a backup, just in case things go wrong. Also, you can check the backup if and when you decide to add the tech back into your games.