Lowering replay value makes a game weaker.
That's my point in case you didn't get it.
It seems you are not a min-maxer and as such you don't understand the need of having more options as opposed to less.
This FIX doesn't lower the replay value. It increases the overall value of the game as a consistent experience. That has nothing to do with min-max strategies since that glitch shouldn't be in the game from the very beginning. Basic balance is crucial for a game and min-max strategies can only be build based on that basic balance. Without basic balance a game like D:OS is pointless.
A cheat trainer gives you all the "options" (aka cheats) you want.
overpowered is having 100% or more resists where enemies cannot hurt you, or turning invis/sneak to end every turn so enemies dont even fight back. That is the real definition of overpowered.
all these books did was allow you to play the game without exploiting other things, like sanctuary robot henchmen.
that should be disallowed as well. the ability to use henchmen in sanctuary as crafters.
force people to dump points into blacksmith and crafting to get those bonuses. its overpowered to exploit mechanics like that!
I agree with all of these points. But that doesn't mean that you shouldn't fix other glitches or balancing issues. One fix at the time...

Other fixes that should follow:
1) Essence coating of armour should be limited to +5% per esseence. Together with the already reduced effect of "weather of storms" this shouldn't make it so easy to get 100% resistancies against every element. Essences shouldn't be available at shops, only by enemy drops.
2) Henchmen shouldn't have points in crafting/blacksmithing/leadership by default. Players should be motivated to invest points in these abilites (trade-off).
3) There should be a "decloak invisibile targets" spell which allows enemy casters/priests to locate and attack chars in invisible/sneak mode in turn-based combat.