The default roost bars are really low. Without a photo of your actual coop I'm not sure where your new roost(s) sit, but they really should be about here at least, if there's enough headroom and landing room:We've changed out one of those bars to a 2x4. You can see the nesting boxes sit lower and to the right of the bars. While the roosting bars are technically higher than the nests, it's not by much.
The bar that's directly in front of the nests is in an awful spot, any bird roosting there could poop into the nests. Roosts should be a minimum of 14-16" apart and 12" away from walls (or nest box entrances). How wide is the coop (internally)? With 3 birds it's possible a single roost will do so no reason to have the 2 bars.
if they consistently go there every night, they must like it. I'm just getting more familiar with keeping chickens and I was debating putting it higher based on what most people said. That window they are roosting near doesn't have a draft, but if I were to move it higher there could be a draft. It's not too cold here at night right now.