Thanks, sounds like I’m out of luck with my AMD CPU on the 16 then. The deep option doesn’t appear in /sys/power/mem_sleep so setting mem_sleep_default would do nothing.
Lack of S3 sleep seems like a UEFI or hardware problem. I’ve tried enabling S3 through Universal AMD Form Browser but like this post, my OS fails to resume. (Be careful with this tool - bricking risk!)