if I may throw in a mini digression for my own situation:
1. Ripped most of my small collection with a 2008 imac and itunes, mostly into lossless as offered by itunes of the early 2010s. They show as m4a, called AAC @ 256kbps bit rate, 44kHz sample, about 4mb for a two minute song. I assume this is decent enough not to bother re-ripping, but what about going forward (I just downloaded fre:arc which looks promising and offers all relevant formats)?
2. been on Sonos for 2+decades so unllikely to use iTunes for any management but wondering if keeping similar formats in the library has any reason or consequence (i.e. mixing flac/m4a/wav in a single library). I don't remember (and paid little attention) to error issues (rarely streamed from my collection, used Rhapsody for access to much larger catalog, at pretty high and easily detectable compression). I guess I am still figuring out which management software I will use, but SONOS to lossless library on NAS or HD of the sweet little old iMac who is still kicking (but maybe ready for sale or retirement) is plan for now.