I think it is possible to do both, based on our own experience.
DS9 is doing an online Algebra course. I have read (and questions from friends) why is there a need when eventually he will be taught these too in Middle/High school. If he does it now, what is he going to do when he reaches MS/HS?
I have similar concern too b4 I started him on the course. Then I came across a question. "If a child can run fast (and enjoy doing it) , would u ask him to slow down?" I feel this is the same as ds. At this moment, I am not going to slow him down. I will also not think abt what he is going to do when he reaches MS/HS because, to me, learning is endless. There will always be things for him to learn on the subject.
Apart from this "acceleration" on Math, Ds9 has other interests too. He likes to cook and he has his own cooking blog. He likes fixing NXT, modelling clay and read. He goes to TaeKwonDo classes 3x a week. These are things that he likes to do.
As for your ds who in love with vocab, I found this book in the library which I think he will like. L Is for Lollygag: Quirky Words for a Clever Tongue. Good luck with your decision.
I agree with you, I think its ok to let them accelerate. Interests can go in spurts so I think its fine to let them go at their own speed as per their interests. There will always be more to learn.
