Why? She could just stop replying.
You don't need to gang up on people just because you don't agree with them, or you feel defensive about something they said (and at no point did I criticise individual women for not breastfeeding, even though multiple people implied I did).
I criticised society in general, and the formula industry specifically. Because they've caused the situation where people act like it's a choice between apples and pears.
If you went to a human mother who didn't live in that society and asked if she'd rather breastfeed her baby (or ask a friend/relative to do it), or sexually assault some cows, kidnap their baby, steal their milk, send it to a factory and add a load more ingredients (potentially including bacteria, melamine, or heavy metals etc), send it halfway across the world, and feed it to them from a plastic bottle, she'd look at you like you were mad. Because you would be.
Re the science, methods already exist for removing/reducing phenylalanine from food. So it could be done in e.g. a local lab or hospital, so women deliver a batch of breastmilk, and get a processed batch back. I don't need to be a biochemist to know it's possible. Just an open mind about how to do things differently from how they are done now.
But this is a condition affecting 0.01% of the UK population. So I'm not sure how that (and other similarly rare conditions preventing unaltered breastmilk consumption) is relevant to properly supporting everyone else to breastfeed. Which HVs won't be doing if they are promoting C&G.