Something that have been annoying me in the game is that it kinda overly rewards you to avoid researching or trading techs other than the ones you strictly need, that is, save a few rare exceptions it's generally never an optimal choice to research "outdated" techs since they make your cutting edge tech considerably more expensive.

Would it be possible to mod the game to make it so the techs of a given Era only take in consideration its own Era in terms of scaling costs? In addition, for balance sake, each Era would need extra flat costs to compensate the loss of the scaling with earlier Eras, plus might be better to make so to get to the next Era a faction strictly needs technologies of the Era behind it, instead of just the number of techs researched mattering.

Would these changes be even possible though?