What my mum always did for my siblings and I, and what I now do for dd and still for myself when its cold, is run some hot water over the weetbix to soften it, drain the water, then put in a splash of milk for taste. Whether its ebm or regular milk is obviously personal preference You dont need as much because it's already softened enough to eat, even without milk.
Could you do that? If you wanted to express it'd make it easier because you wont need so much milk.
I dont think I gave DD weetbix until about 10 months, and at that age I gave regular milk with it, as she was nearly 1 anyway and has milk in other things and never had any reactions.