In a school like my sons, these children will blend - something which I was looking for for my son.
This, for me, is the single most compelling argument for selective education. Yes I would like to see DD challenged and to learn to work rather than coasting, but most of all I want her to be among a peer group so that she doesn't feel like a geek and a freak.
It is easier to blend in a school were everyone else is like you. Whether a child that is different will be made feel like a geek or a freak will depend on the cohort and the school ethos. If the school makes it unacceptable to treat children with SEN different or calling them names, then the same behaviour should be expected for children at the other end. In a classroom were children regard each other as a valuable person, independently of whether they can barely count with their fingers or read or are actually reading chapter books and doing complicate mental maths, either child would be happy and integrate well despite their differences.
Regarding homework, DS in Y2 gets weekly homework, always marked by the teacher with feedback (state school). My nephew is in Y7, and he also gets homework weekly in all subjects to an appropriate level (state comprehensive school).