Hey JTViolet!
I’m not Lincoln, but I do have an answer: I’m currently testing AmpliPi with 64 bit Raspbian Trixie so this is on the way to being solved.
This is part of a greater scheme to overhaul the OS, partitioning scheme, and update workflow so it may be a while before there’s any released results from that, and it may be even longer before we support multiple Airplay 2 streams after getting the overhaul out in the first place. In short, this is on the active docket and should be out in some number of months that I’m not prepared to estimate beyond “By end of year, ideally by end of summer”.