I suspect that a lot of people using Roon ARC have iPhones. There already is a request to have the ability to convert downloaded songs/albums to lossy formats to save space on our smartphones, but I want to point out that the iPhone (or at least AirPods Pro) only accept AAC.
Yes, we can download/stream to FLAC and then the iPhone will convert to AAC before sending to the AirPods Pro, but that would take up a whole lot of data/storage space on the iPhone.
So, basically, for the iPhone it would be great if we could stream/download our local library in AAC format.
You can listen to mp3s via the AirPods. The iPhone will simply convert the mp3 file to aac before sending the signal to the AirPods. Lossy to Lossy conversion is something I’d like to avoid, and I’d like to save on data use/hard drive space, as mentioned above.