I have submitted a bug and a couple of feebacks on very frequent crashes of the Computers App when I try to play from my iTunes libraries using Home Sharing. The same libraries work just fine in tvOS 11 (I still keep an AppleTV 4 on 11 just to play my music but accidently upgraded one because it constantly asks even when you turn automatic updates off, but that is for another day).
The two feedback reports are #5095684 and #5114558 and have logs attached. My bugreport.apple.com bug is 43767599. One shows the homesharingd getting shut down by a watchdog process for taking up too much memory, the other shows some other kind of out of memory error on the homesharingd process.
My iTunes Libraries are large, 88K and 98K songs.
Again, tvOS 11 works perfectly, tvOS 12 crashes almost constanly going back to the Computer selection screen. Sometimes just viewing the list of playlists, sometime during playback.