Not sure why all the complaints about homework.
My mother in her capacity as a teacher at a private primary school on Kenya, had some Koreans and some Japanese pupils. Same school I went to.
Their parents expected at least 1 to 2 hours homework per day and got extra tuition on Saturday mornings.
'Junior' (Japanese) was 7. He was in the class below me as I was 8. He got promoted to our class after only a couple of weeks. He then stayed in our class for 2 months. Then he got shifted upwards to the year above.
The Korean kids were speaking English in 8 weeks and most of the other far eastern pupils way ahead of their counterparts.
I don't see the problem with say a half hour per day during holidays. You could exclude summer so that they get a total break from it.