Okay, well, I guess I shouldn't put it that way for SP only. Maybe more like, if you can survive early wars against the highest level AIs you play against with those nations :P Because yeah, it's mostly the first year/year and a half where production is relevant in vanilla no matter what scales you take.
I'm not going to tell you whether you *should* use CBM for playing in SP. Personally that is my preference, and I could make arguments like "cbm makes the summons the AI uses better, thereby making the AI better", but that's about it. CBM isn't going to make vanilla any worse though, and I think it's definitely worth at least trying out to see if you like it. If not, no harm done. It should at least shake up your usual gameplay a bit. You will have to relearn some things... but IIRC it's only a handful of spells that have been moved around, mostly spell changes have been changed in other ways. And descriptions have in fact been changed where appropriate. Anything that has new abilities should have descriptive text saying so if the abilities aren't obvious, and spells basically update their own descriptions so that part shouldn't be a problem. It is true that there is some re-learning to be done, but there's not really the feel for me like the entire world has been changed
Basically anything that you could do before with spells you can still do now. It will just sometimes work better.
The biggest changes to wrap your mind around IMO are the changes to magic items, because CBM has made pretty heavy adjustments in that area to make underused things more viable, and especially in response to the loss of hammers as a massable item. Luckily there is a handy CBM forging guide you can refer to when trying to figure out path requirements.