There is a big gap between meal and b/feeds, I would guess that could by why he's not interested in snacks.
Could you give him a breastfeed within a 1/2 hour of eating lunch? That way he's having a bf long before he goes to sleep at after 2pm.
Don't know about whether to drop the second breastfeed... perhaps when he shows less interest in it because he is getting enough from other meals.
Another option could be:
breastfeed when wakes then 7am breakfast,
9/9:30 snack
11:45 lunch, then breastfeed after
2pm have snack (or after he wakes at 4)
dinner 5:45-6pm
breastfeed any time between dinner and bed.
depends how that suits you!