The problem with options is that the game difficulty has to be balanced arround something.
If the game is balanced with "cheese", it will become very hard or frustrating without it. If not, it will be very easy using these mechanics.
I'm nearly sure that's exactly what happen at the moment and why the game is very hard to some players and very easy to others.
I think the best solution is to find a compromise instead of thinking about toggle on/off everything.
I'm not sure you can properly balance a game difficulty for 2 completely different systems.
Frankly, I consider the Larian cheese more of an I-win-button/easy-mode than something the game is balanced around. Sure, it's harder without using it, but definitely doable. Even solo. Even so, I may refrain from using the cheese, but just knowing it is there makes me feel like I'm engaging in a self-nerf/fighting with a handicap and this actually limits enjoyment a bit (especially when I think of the many better ways the resources should have been used). I would have an easier time of it if instantly winning by pushing the boss off a cliff also, or exploding enemies with barrels, meant some magic item/loot would be lost/broken/burnt. Risk vs reward would be more balanced again. I want to not feel like a fool for not doing this the easy silly way. I want a concrete reason.
I agree an option is the last resort, only marginally better than nothing. Larian's cheese can be fun, but shouldn't be a core mechanic and rather be scaled back to become a situational tactical option. For instance, Shove is implemented in an objectively overpowered, unbalancing (both shove and jump favors strength builds) and immersion breaking way. So unnecessary! The fun can be had using D&D assets or homebrew with internal logic. Magic Hand, Thunderwave and Repelling Blast is already implemented. It could be expanded with a wand or a magic item/weapon that made the user charge and shove at the end, or a tadpole power. This would in my mind solve the unimmersive cheese and retain the fun.