I use the Brinsea brooder plates, too. They are the best. I assume the chicks will be indoors?
Yes, you have to "show" the chicks where the heat is. Just like you have to show them the food and water. You can adjust the legs, so the back are a bit lower than the front. That way the chicks can decide how much heat they want. You may have to stuff them under the heater a few times until they get the hang of it. I have had a chick wander out from under the heater at night the first night or two, and not be able to find it's way back. Chickens have horrible night vision. I sleep out in the living room where I brood the chicks the first few nights, so I can hear them if they are in distress. This has only happened a few times and after the first few nights, they get the hang of it.
Good luck with your chicks!
Photo below of some of my chicks using the brooder plate.
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