Cool project!
On a side note. How do people deal with all the ugly mess birds cause in such settings? I'd love to have such thing but seeing all the white stuff on glass door does not really feel fun to me overall.
Sounds like you've got birds crashing into the door? That's often something that can be improved (with stickers or hanging decorations) that make the glass more perceptible to the birds. (Another thing that sometimes helps is having bushes or shrubs, or even potted plants, in sight of the feeder - most small birds will use a "staging area" and fly somewhere nearby first, "check out the scene", and then fly to the feeder from there; it doesn't really control the activity, but it adds some options.)
What do you mean specifically? These birdsong analyzers are sensitive enough that they do not rely on setting up a feeder. It’s obviously dependent on where you live, but in the Nordics, living outside city centres is good enough for both background noise and birdsong from nearby trees/parks/forests. Privacy matters aside, setting a mic up on a balcony or window is enough. Another solution is feeding data from a cheap security camera with a mic through wifi. This way the camera can stay outside in different weather, it’s not super close to you actual living area and splitting audio from the RTSP stream should be relatively easy to be analyzed by BirdNET.