With my hundreds upon hundreds of chicks I have raised, I've never had the issue of them eating shavings. I have with sand, and saw dust.. but the shavings are simply too large.Yes,the Brinsea brooder is excellent.
Regarding shavings,i usually recommend to new chicken keepers to use paper towels for 1-2 weeks b/c i have seen chicks eat shavings(or not eat at all if they do not recognize feed) and while i would know what to do in this event,a new chick owner may not and this could possibly cause the death of a chick.
I have found that if I add shavings in after a week, they seem to think it is food at that time rather than starting them on shavings straight away. They don't eat them, but they play keep away with the large pieces and chase one another around. If they really wanted to, they could try to eat it.
I think sand is a very dangerous bedding to use for chicks personally. Nothing wrong with paper towel, it is just not environmentally friendly, and it can get very expensive. I can use a roll up in a couple days. I find they get really bad poopy feet with paper towel - and that can be terrible with feather legged chicks.
It is easier to get them to start eating on paper towel, but I wouldn't bother continuing to use it after 4 days old, as they are simply poop machines, and should know what is food at this age.