Technically, having a machine sleep defeats the purpose of using any device as a Roon core
I’d argue I can make assumptions about when I am unlikely to access this machine. eg between 11pm-6am in the majority of cases. I’m not serving content globally, just to my household which exists in a single timezone. For those late night parties I can go and turn the Mac back on 
Having it always on in the middle of the night is a waste of energy and that being a requirement for it to function correctly is poor design. No other application I use requires a restart.
You had mentioned that you were running 12.6
Indeed though, between opening the ticket and getting a response Ventura came out. Either way, the setting is available but hasn’t fixed the issue as for better or worse OSX still forces the machine to sleep.
An important detail is that the Roon endpoints (Pis) work fine, its only airplay devices which don’t function until Roon is restarted. So it’s likely related to functions that discover / track airplay endpoints. Arc works fine between sleeps, so seems like a regression only impacting Airplay as this was fine pre V2.
I have some vague memory that I had this issue ~2 years with the last major update but it was later fixed in a subsequent update.
Edit. Actually it was slightly different with USB devices being unavailable in 1.8 USB Dac endpoint becomes unavailable since 1.8